Under seat carry-on only -- Not sure I can do this

If you do want to learn if your chosen seat on a plane has one of those metal "entertainment" boxes blocking part of the under seat space directly ahead of you, I've found that I can usually find that info by entering my flight info into seatguru.com.

Maybe roll in a cube or two? I'm an average sized female but apparently taller than my friends, and I am able to fit in my 16 x 13.5 x 6 underseat bag: 1 pr jeans, 1 pr yoga pants, all unders, at least 5 pairs of smart socks, flip flops, 3 long sleeve tee shirts, one over blouse, PJ's, a DSLR with one lens, all electronics and cords; ie iPod or iPad, battery morphie, all toiletries, and a bedside quilted bag, an empty purse, some small snacks, ...and I'm sure there is something else. I have a tiny crossbody with my ID/PP, financials and my meds that fits under my jacket, but would squeeze into my bag. This does not include what I'm wearing.

I packed my husband's Eagle Creek wheeled tote, 13 x 13 x 8(?) recently and he couldn't believe what I fit into it, granted his was a short trip, but he's 6' with an average build: Cotton underwear, socks and 2 cotton tee shirts, 2 longsleeve travel collared shirts, lounge wear(top and bottom), 1 pr slacks, toiletries with razor, DSLR and accessories, iPod and accessories, his meds (which take up a lot more space than mine), leather belt, eyeglasses, and I'm sure some other sundries I don't recall, so just experiment a bit rather than just folding them in. I know I could have fit at least one more shirt in, and a lot more if he switches to a smaller camera....I think he's going for a fujifilm camera so he'll have oodles of room next time.
Also, before picking your seat, look at the flight on seat guru and make sure you don't have the entertainment box at your seat. We've yet to not be able to fit our bags under window or aisle seats...and middle seat space is usually larger...we just don't sit in those.
This being said, when traveling abroad I like my luxuries and don't see myself packing this extreme for a 2 week trip unless I can't manage any more, instead I check my 21" wheelie, usually, and just carry on my necessaries for the underseat bag. In my 40+ years of travel I've never had a lost bag.

Paul, a lot of people will scoff at it, but have you considered using a Scottevest or something similar? You can carry a lot of things in the vest, freeing up space in your bag/personal item. In fact I think they have run contests with people traveling with the vests only.

But there's nothing wrong with plusing-up your supplies when you get there. A few minutes of shopping and you can find more of anything you need. PS, I only take the shoes I'm wearing anyway.

Some airlines have the extra low economy fares that only allow one "personal" under-the-seat bag on board, no overhead storage allowed. (I'm not sure how the cabin crew enforces the no overhead rule).

If you use the fishing vest stuffed with stuff in addition to your under-seat storage allotment, ask yourself if you will be comfortable sitting on an overnight flight with a vest stuffed with stuff in addition to not being able to stretch your legs because the space under the seat is blocked with you baggage. That combined with the narrow seat and short pitch.

I have noticed, at least on American Airlines, that the latter boarding groups sometimes have to gate check a roller bag, but rarely have I noticed a duffel bag or a backpack having to be gate checked. I fly standby almost exclusively (retired from AA) and since I might get a seat at the very last moment, I pack assuming that I might have to gate check something. If I were you, I'd go ahead and pack either a backpack or duffel and then also your "personal item". Perhaps make sure that "if" you had to gate check the backpack or duffel, that you have all of your super-important items stored in your personal item. Another thing that I do is to put at least some of my clothing in a packing cube and put that in my roller bag (if I am carrying one)...that way if they do make me gate check it, I can pop out the packing cube and be assured that some of my clothes will be going with me in the cabin.

Travel "comfortably"! Don't try to pare down to the point where you will be sorry you brought only basically one change of clothes. Unless, of course, that's what makes you comfortable!!

My son carried a backpack only for our 21day best of Europe tour. He took:
2pair jeans, he wore one on plane
2shorts
Shoes on his feet only
Underwear for 10 days
5thin T-shirt’s
I don’t think he shaved much. Took toothpaste/brush and safety razor.
I was upset when he got in the car to head to the airport. He had more clothing stuffed into or laundry bags both times we had access to laundry than I did.
I did sink laundry along the way.

With a Scottevest, you won't even need a bag.

http://www.rtwblog.com/about-the-challenge/

What do you have in the bag besides clothes? It’s pretty easy to fit enough clothes in an underseat bag if you feel the need. To me the minimum would be what I’m wearing plus 4 quick dry underwear, 1 pants/shorts and 3-4 additional shirts. That gives you 4-5 days of clothes, I don’t wash pants all that often so 2 pairs is fine. Wear your jacket on the plane along with heavy shoes, pack a very light pair like sandals or canvas sneakers if absolutely necessary.

The issue seems to come with the other stuff - books, large toiletry bag, multiple pairs of shoes, electronics. Will you have a laptop or large camera? If so can you downsize to a phone and iPad? Books? If all you have in the bag are 5 days of clothes, basic toiletries, and a phone and charger you should really be able to do it. If you are motivated.

I wouldn’t do it (I carry a DSLR camera that makes this impossible and the camera is a priority to me). Also I like having a bit more clothing options, but I think it can be done if you really want to.

There are many blogs and vlogs from folks who have perfected ultralight travel for extended periods. If you go researching the practices, avoid any “minimalist” sites. Minimalism is a meaningless web traffic generator these days.

A few things that seem to be common among the best ultralight practices: make a pile of the absolute essentials (things without which life would be at risk) that includes stuff like meds; make a pile of clothing: pile of toiletries; everything else. Then: remove everything that can be purchased at destination; make a new pile of everything that can be worn in transit; reduce all else down to bare necessities (no cameras, Laptop, big headphones, or jewelry). It is possible to spend a great deal of money on specialized clothing and accessories for ultralight travel.

It is a simple process to trim one’s travel wardrobe and accessory bulk down to almost nothing but it takes a mental leap and a commitment to a certain level of physical discomfort while being comfortable with the risk at weird is going to happen for which one is totally unprepared.

Tom Bihn ultralight thread
Carryology ultralight list
women’s ultralight list

Edgar, I'm guessing that because Basic Economy boards last, there is no overhead space left for them.

I have no plans to travel under seat only-will stick to personal item and carryon only. I have made several trips with no shoes except the ones I was wearing and never had a problem but I won't ever do it again because of something that recently happened at home. I put on my hiking boots(probably at least 10 yrs old) and was about to walk out the door when I noticed that the sole was coming off. The same thing happened to the pair they replaced. If this happened to my only pair of shoes on a trip, it would be a problem. So I won't be able to pack quite as light in the future. On the other hand, I am more and more just packing clothes that will dry quickly so I can take fewer. And my new Magellan Voyager, that I will wear on the cold plane, can substitute for both a purse and a rain jacket.

Legroom under the seat in front is especially important on long-haul flights.

This is an update to my first post about avoiding having my bag gate checked on a full flight. (Thanks for your comments and suggestions.) My experience is based on six recent flights, all on Delta and on some smaller jets (MD-88, Bombardier CRJ900).

I ended up traveling with non-roller bags, a duffel-like backpack on two flights and a normal, somewhat squishy duffel on four. Bottom line: (Unscientific, I acknowledge) If your bag doesn't have wheels, the gate attendants will let you carry it on, regardless of whether the flight is full and seemingly without regard to how big your bag actually is and whether it really would fit under the seat.

My bags would fit under some of the seats, but not all. Because many roller bags had been consigned to the hold, however, there was space in the overhead compartment on every flight I took for my bag. I worried about it before boarding every flight, and was prepared to pull out the essentials from the larger bag (I packed a smaller bag within the bigger bag), but I never had a problem. Your mileage may vary.