Lauterbrunnen and Tuscany in June...help please

Well, I've been to Cinque Terre, and many other places. Cinque Terre is a lot of walking, and up and down hills. You will want something like a sport sandal you can hike in. I highly recommend Keen sandals, especially the Keen Venice H2. Google it and you will see many. The Keen Whisper is also good. Or you could go with Ecco Yucatan. Shoes are the most important part of your wardrobe.
Beyond that..here is what I take...
2 pairs of lightweight, sink washable, black pants. I get mine from Www.travelsmith.com. I also have some llbean travel pants that are nice. I take long pants but capris are also ok. Shorts...no. Just for beach areas in Europe.
With my 2 pair of pants (wear one on plane), I take 4 or 5 shirts. I like the travel shirts that have long sleeves that can be rolled up and fastened to be short sleeves, I like to take 1 or 2 of those travel shirts. And 2 or 3 pullover, t-shirt type shirts. Always at least one of my pullovers is black. (The black top and pants, with a colorful scarf and jewelry, is perfect for evening). Of course I wear one of those shirts on plane. 3 or 4 pair of quick-dry underwear, 2 bras, one nightshirt, one swimsuit and I take a very thin, light pareo if I think I'm going to be swimming. A very lightweight waterproof hooded jacket. A couple colorful scarves. A couple pair smart wool socks. A cheap pair of flip flops.
Now I'm wearing one pants and shirt, plus a long sleeve shirt as an overblouse, one underwear and one bra, and my walking sandals. That means my bag has: one pair of pants, 3 or 4 shirts, 2 or 3 underwear, 1 bra, possibly a swimsuit, my rain jacket, 2 socks, flip flops, nightshirt and 2 scarves. Not much of a load at all! Of course be sure to take sink stopper, laundry soap and twisty clothesline. I wear pants for 2 days, so I do laundry every other night.
If you pick a rain jacket that isn't too sporty in a neutral color, it can double as an evening jacket. Or you can do a pullover under a long sleeve overblouse.
I generally get very similar colors. Black pants. Black, white and maybe grey, green or blue tops. Black or tan rain jacket. Black sandals. Black is very popular in Italy.
These clothes will take you anywhere you want to go, you will be packed light, and you will be happy!

I think you received some good advice about packing light, but I have been to Europe just about every summer for years. Really there are more tourists than locals about and you should bring the clothes you normally wear and are comfortable in. It is going to be hot in June and if you are the type that normally wears shorts, bring them!!! Of course you don't want anything crazy short, but trying to blend in is a joke. Everyone looks like a tourist. Wearing all dark colors trying not to wear shorts, I have done that and really regretted that I did have anything cute with me. Even shoes, now just about everyone is wearing colorful sneakers even in Europe. I think you will really regret not having any shorts and also trying to look "European." Pack light but bring your own personal style.

Well, I guess I object to the idea that it isn't possible to pack as I do AND look cute. I think my clothes are always very cute, and I like black. And saying no shorts isn't about trying to blend in; it's about being respectful. Even the Rick Steves packing guides steer away from shorts. Many places (like churches) you can't go in shorts. I find that the lightweight travel pants or capris are plenty cool for summer.

Italy seems to have been addressed, but not Switzerland. You'll need closed toe walking shoes or hiking boots depending on your level of activity. You'll need a wool sweater to go under a hooded windbreaker, maybe a scarf if it gets cold and possibly heavier pants depending on the weather. Leggings under light pants can do if it gets cold or if you go up the Jungfrau or Schilthorn. You might want gloves if you go up to the glacier. The weather is unpredicable in the mountains.
I too wear a lot of black, dressing it up or down, and have done so for years, wearing the same clothes overseas as I do in the US. If you do wear black, be careful about ticks in grassy and wooded areas, even in Switzerland. Some things even the Swiss can't perfect.

Good point about Switzerland. I take silk long underwear, top and bottom. These are perfect to sleep in, so you can skip the nightshirt. If you wear the long underwear and a long sleeved shirt with the black pants, smart wool socks with your ?Keens, and your waterproof hooded jacket, you should be fine. You already have a couple scarves. Just add the long underwear and you will be all set. Keen are closed-toe by the way.