I like to wear a dress - one of those comfy, casual ones, relatively wrinkle-free of course. It lets me layer.
If in summer, I'll wear a sleeveless denim dress, for example, and layer a tee or a tank underneath; then a cardi or a light jacket on top. All things I can remove if it's too hot (in the washroom of course). I bring a pair of thin leggings in my purse - or wear them - to be put on if AC is too cold. I always carry a pair of socks, as I remove my shoes in flight, and find it is easier to sleep if all parts of my body are warm.
A pashmina-type scarf is also a good idea as it can double as a mini cover or even rolled into a pillow!
In winter, I'll wear a wool dress with basically the same elements (thicker leggings, turtleneck instead of a tank...).
I find a dress to be easier and less restrictive than pants.
If all that sitting leaves me bloated, I am less self-conscious in a dress arriving at the other end.
If something spills, it is easier to quickly rinse the stain in the washroom and have it dry than if it would be on close-to-skin pants.
I also try to wear my bulkiest shoes, but not if it means wearing my trainers with a dress.
I avoid earrings, as they make it less comfortable to sleep or can get caught in the above mentioned pashmina.
