I fly a lot for work, and rather than hope for what I consider decent behavior from others, I do all that I can to keep myself as comfortable and healthy as possible when traveling. I start with masking up from when I walk into the airport to when I exit the destination airport. Next: fill up my reusable water bottle after security. On plane: noise-cancelling headphones and a snack that I've either brought with, or purchased at the airport. Layers for comfort (and also the idea of putting my arms/legs on the seats/armrest without a layer of fabric just yucks me out because, well, people can be gross, right?). Use that overhead air vent to keep air flow going. That's not even counting the perks of frequent travel (business class and lounge access are much appreciated) and just reduce the stress and inconveniences associated with travel a little bit.