Dressing for Europe

Before thinking about clothes, you need to investigate the Schengen Agreement. It basically limits tourists to being in much of Europe for no more than 90 days out of any 180 day period of travel. The UK is not part of the agreement, but many of the other places you mention are, and that is going to cause you problems. There in NO LEGAL WAY to get around this. In order to say longer, you MUST get a special visa from at least one of the participating countries and it will have specific limits.

Now to clothes. Layers are what work. While I haven't done such a long term trip, I usually pack 3 pairs of pants (plus wear one) and a mixture of 5-7 tops (some button up, some Ts/turtlenecks and one or 2 short sleeved or very light ones). I take a waterproof, lined, hooded coat along with a hooded scarf (I don't do hats) and gloves. Plenty of undies and bras and socks and I wear waterproof shoes. I take extra sole liners to swap out. A couple of dress scarves for dinners. All pants are black or khaki or grey, and all tops are red, black or cobalt blue or purple and co-ordinate with each other. I would expect that you can rent ski equipment and buy or rent ski clothing.

I'm assuming you are an Aussie of fabulous mixed heritage and so have a European passport so can thus travel freely.
Is your plan of attack something like this?
June - UK (and Ireland?)
July - Begium, Holland, France
August - Italy
September - Spain
October - Greece (and Croatia?)
November - Hungary, Czech Rep, Austria
December - Switzerland and Germany

Schengen Agreement doesn't apply to Australians, I believe. When I did a 3-month trip at 25 (and dinosaurs roamed the earth) I sent clothes home as the hot weather disappeared, bought sweaters as needed for cold. As noted, layering is key so you have multiple light layers instead of one heavy coat.

That's a large range of weather, June to December, skiing, etc. The question will be whether you can, realistically, get adequate clothing, for that range of weather conditions, into one backpack.
You might have to choose between 1) adequate clothing, or 2) more than a backpack.
Also, you mentioned shorts: in the more famous Rome churches, your knees and shoulders have to be covered.

Will layering be enough to keep the cold 0 degree nights of walking around the Christmas markets? So maybe a pair of thermals as well then?
Yes David you would be correct and we both have fabulous British passports! Schengen will not be an issue. And you would also be on the right track with Itinerary too: (not that it is set, still working through the best way to do it)
June: UK and Ireland
July: France (northis bits), Netherlands, Belgium
August: Germany (northish bits, Berlin in the nicer weather)
September: Italy, Greece
October: back up through Amalfi coast, Southern France, Spain
November: Morocco, Austria
December: Germany (southish bits, Munich), Norway (or next best for Lights)

Thankyou Kent .. this is the stuff i need to know about knees and shoulders!

SazMcG,
You're welcome, glad to be able to help.

Saz I would guess mailing clothes forward, or shipping excess home will be more expensive than just buying anything you need (that you didn't pack) over there - second hand shops if necessary. On some trips, I have packed old clothes and discarded them or replaced over there.

If you want to see what people on the street wear, find a few sites with street view webcams or even watch the Rick Steves' videos and you'll see.

I am very envious. Oh to be young again. I was 24 when I did my year travelling and working in Europe, but that was 26 years ago. Still, I made some great friends. After summer in the north I would fly to Athens and do the Med in one broad sweep, east to west ...
June: UK and Ireland
July: France (northern bits), Netherlands, Belgium
August: Germany (northern bits, Berlin in the nicer weather), Prague
Fly to Athens from Prague
September: Greece, Italy
October: Southern France, Spain
November: Morocco
Fly to Vienna from Marrakech
Austria, Switzerland
December: Germany (southern bits, Munich), Norway (or next best for Lights)

You will only need summer clothes + light sweater + light rain jacket until you get to Austria in November. By then you will probably want to burn the entire contents of your backpack - chuck out or mail back the really light stuff and buy heavy sweater, coat and boots. Strappy shoulders and bare midriff are great for music festivals, sometimes not so great for getting into a cathedral. Now i am having flashbacks to the odour my back pack took on, and the numerous morning 'sniff tests' before dressing. Eeewww.!!

It's July, I am in Germany now, and I could use a sweater.

Layer, take some things you won't mind leaving behind, buy a few items as you need them.

Good tips Stan and Zoe.
david - that does seem a much better way to connect the dots and try and keep in good weather til the very last moment!

I suppose what im wanting is to not stick out like a obvious tourist sore thumb, if locals dont really wear shorts then i will pack dresses or skirts, but i would imagine it will change from city to city. I wonder if you can fit a pair of thermals under a pair of jeans, i will have to try it out!

Schengen absolutely applies to Australian passport holders

http://www.smartraveller.gov.au/zw-cgi/view/TravelBulletins/Europe_Schengen

As to thermals under jeans, yes of course, as long as there is room. I wouldn't wear short shorts or bare midriffs in Italy, etc.

Hey Tom, they have British passports. No problems.

It's all about layers. Layers will help you pack for all conditions. I'd skip anything cotton. I adjust my pack list a little for colder or warmer weather, and for more or less dressy travel. Here's my (guys) basic list:

Outer wear:
1. A good waterproof rainshell with a hood and long enough to have rain drip past your bottom is useful.
2. Warming layers. I like layers that can be used separately. My favorites are a thin washable merino wool sweater and a lightweight full-zip polar fleece. They pack light, and not bulky, but make a good intermediate layer.
3. Gloves/scarf/hat. I like to pack some kind of hat, usually a lightweight ski cap. I don't pack an umbrella, gloves or scarf. When it gets cold or wet, it's easy to drop into a store and buy those.

I think you can get down to freezing weather packing only these and layering them all together. You can also put on only the rainshell, when it's wet but not cold, or the sweater for dressing up a little in cool weather. The fleece can be outer wear in cool but dry weather.

Basics:

1. Underwear - I pack three pairs of underarmour 9" inseam boxer jocks. I wash a pair daily in the sink and it air dries easily. I pack three pairs in case I have a day when washing is impractical, I change after a particularly sweaty hike or I lose a pair.
2. Socks - I always pack three matching pairs of non-cotton socks. Most of the time I pack a black crew sock - because it can dress up or down. I pack matching pairs because I can lose a sock, or wear one out, and still use the odd one. For casual travel and cold weather, I'd go with good wool hiking socks. They will be more comfortable in warm weather and keep your feet warm as it gets colder. I'll also hand wash a pair of these daily.
3. Shirts - I pack five shirts. Some combination of t-shirts and button up shirts (maybe a polo thrown in). The t-shirts are or similar to adidas solid color "clima-lite" shirts. They can be outer wear on warmer casual days or layered under a button-up shirt or sweater in cooler weather. They hand wash and dry overnight easily. I'll wear them one or more times, depending on whether they need it, before handwashing. I prefer long-sleeve button up shirts (think northface). They look decent when you have to dress up but can also be handwashed and air dried as needed. Long sleeves are more flexible. When it's warmer or more casual, I'll roll up the sleeves. Long sleeves gives you the option to either roll them up or keep them long for colder weather or more dressed up look.
4. Pants - I pack two pairs of pants plus one other bottom. I love golf pants for travel. They're light, pack easily, don't show wrinkles or stretch the way cotton would. They also handwash and air dry easily. They can be casual or somewhat dressy. A pair of black pants and/or a pair of tan/khaky pants cover a lot of dressing options. For really casual in cooler weather, I like athletic warm ups (knit and slim fit) in a neutral color like gray or charcoal. They pack easily and can be washed and air dried. They're perfect to wear to a laundrymat on wash days (for me about every two weeks). I don't love jeans for travel, they're too hard/expensive to wash and dry, stretch as you wear them (and need to be over-dried to get back in shape), and bulky in your bag. If you're set on jeans, go with a lighter weight fabric, darker and more fitted - those are really common all over Europe.

For summer travel I go with a pair of shorts (again non-cotton) that can double as a swimsuit or alternatively a swimsuit with pockets that can be worn as shorts.

cont.

1. Shoes - I normally pack two pairs of shoes. A walking shoe and a light weight sandal or flip-flops in summer, two pairs of walking shoes (at least one that's water proof) in the winter - one for hiking and one a little dressier. I normally shop for lighter shoes to keep the overall load light, but also wear my heaviest things on the plane.
2. Belt - I take one belt to match the shoes. If I have a black and brown pair of shoes, I pack a reversible belt (the only time I ever wear a reversible).
3. Tie - only if I think I'll need one.

Bag. I prefer a convertible weekender bag. It's light and can be carried on. If you find a true backpack that can be carried on and weighs only a few pounds, let us all know. I keep reducing my load, so I'm always looking for something smaller (maybe only a shoulder bag or bigger daypack?), even for a six-week trip (I've never done a six month vacation). I find I rarely carry my bag more than a mile, so a true backpack isn't really necessary.

Ettiquette for short shorts and bare midriff is primarily applicable to churches. I've only seen a dress code enforced in Italy and Spain. The dress code enforced is consistent: knees, shoulders and midriff covered. It's about modesty, not about dressing nice. Sandals or flip-flops are fine. A pashmina scarf big enough to wrap around your waist, at need, as a long skirt works when you really want to wear shorts. Add a light sweater you can put over your sleeveless top and you're in.

It's easy for a woman to really dress up while packing light. A little black dress in a synthetic material that doesn't show wrinkles, paired with a really simple black sandal or flat, looks great. The set takes up almost no room or weight in a carry-on. You can add variety with some costume jewelry or scarf.

Thanks so much Brad ... its a great perspective for a mans packing list for my partner!
I was thinking a backpack simply because i didnt want to carry a case and the rolling ones would be difficult to manage on those cobble street roads and getting quickly in and out of trains .. ive had troubles before! And hopefully a size that is still carry on for ease of travel. But looking at the ways to combine clothes i think its doable for two people .. maybe .. the proof will be in the pudding!
So would more locals wear dresses in the warmer times?

You wouldn't be out of place in a casual dress. It really depends on where you're at. In a city, most people are dressed for work - tourists are dressed more casually but no one cares (some churches and nicer restaurants excepted). If you're at the beach, dressing up would seem out of place. A light summer dress would work either place.

One of the best suggestions I've seen is to use Google street view (in Google Maps) to see some of the places you are visiting. It gives you a view of what people on the street are really wearing.

The hardest part is picking items that can dress up or down, can mix and match everything else (so you can wear it lots of ways), aren't bulky or heavy, are easy to hand launder and don't show wrinkles. There's a certain art to it. I try to make notes after a trip about which clothing items worked well, which I wish I hadn't packed, and what items would have been nice to have. Whenever I shop for any clothes these days, part of the consideration is whether it can travel well.

We did three weeks during late November/early December last year. We both managed with one carry on backpack each (the Cabin Metz worked perfectly!) I wore my boots and heavy coat on the planes to save space in my bag. We visited London, Cardiff, Exeter, Paris, Amsterdam, and Dublin. I was comfortable in every city except for Amsterdam because it was so windy and rainy that I couldn't keep warm and dry (as a result, I spent a lot of time in toasty warm brown bars.) I dressed for warmth and comfort.

Here is the rest of what I packed:
1 pair of jeans
1 pair of slacks
1 skirt
2 dresses
4 pairs tights (1 fleece lined; wore these alone and under my pants)
3 sweaters
2 fleece pullovers
2 thermal undershirts (tank tops)
2 long sleeve shirts
3 scarves (to change up my look)
2 hats (one knitted, the other "stylish")
1 pair of gloves (wish I had two!)
underwear (I packed enough for a fresh pair all 19 days!)
1 bra (wore the other and rotated)
Pajama pants (worn with the thermal undershirts)
4 pairs of socks (bought an additional pack of 6 in Exeter)

We spent 3 days or less in each city so I packed 3 main outfits (and one travel outfit) that I could play around with a bit during our trip. I wore one dress out in London with my husband's uni friends and the other to the Opera in Paris.