i try not to check any bags if i'm gonna be out of town for 5 or less days, try to cop a quality duffel bag specifically for this purpose. even if it's officially a bit too big to be a carry-on, it's collapsible so tsa/attendants shouldn't give you any shyt about it
watch carrying on liquids (there's a tsa approved size if you have to bring them), leave the cologne and shyt at home. pack valuables/fragile items in a carry-on
but yeah, comfortable slip-on shoes, patience, noise canceling (or good isolating) headphones, a spare smartphone battery. i try not to drink before or during flights (altitude + booze can do a number on you, not to mention having to pee on a crowded flight <)