I don't believe anyone has mentioned a super-large, heavy ZIP Lock bag for doing laundry if your bathroom lavatory has no stopper or leaks. (Alternatively, something squishy that will block the drain.)
I've tried regular inflatable airplane pillows (basically C-shaped) and found them better than nothing but not really very helpful, because my head tends to tip forward if I doze off, then I wake up. The J-pillow is better, though not a total solution; I just don't sleep well in a vertical position. I seem to have lost my J-pillow, so I'm going to have to replace it. It appears the design has been modified since my original purchase--one hopes for the better.
My trips are so long that it's highly likely I'll need a bunch of different things at least once. I take most of the things already mentioned but try to make sure everything is as lightweight and non-bulky as possible. I travel with a small drugstore of OTC meds, but mostly just a few of each, and I consolidate them into small pill bottles. I take more of the two things I know are not generally available in Europe: high-zinc-content lozenges (Coldeeze or equivalent) and Pepto-Bismol. We won't talk about the 6 lb. of calcium, magnesium, etc., I head out with.
Although I understand the logic behind the "just buy it if you discover you need it" philosophy, there are negative aspects to that approach:
- You'll probably pay a lot more in Europe, if only because you don't know where to shop.
- You'll probably have to buy more of things like Tylenol than you need, and the per-pill cost will be shockingly high. I don't want to have to carry the excess around with me, potentially for months. Nor do I want to waste money.
- The umbrella you buy from a street vendor (the one RS promises will show up immediately if it starts to rain) will start failing within an hour and be totally useless by the next day.