depends on the season!
in summer, i wear a cute tunic in my signature colors (red, turquoise, pink, etc.) and sometimes a skirt or capri pants. with flats for shoes of course!
in spring, pants and a cute blouse. flats again.
in fall, pants and blouse, again. i take a pashmina in a deep red color and flats.
i haven't flown in winter, yet. my recommendations are flats all the way and avoid too much luggage! drink lots of water! alcohol is a big no-no, NEVER EVER whether in air or on ground! just my opinion!