Avions:
Most avion live in a giant skycastle. Name TODO.
Some also live in tribes, mostly hidden in mountain ranges or forests (sometimes sharing with elves).
Families are large, and tend to have a heavy influence from a particular species of Earth bird.
Genitals less pronounced than other races.
Face starts quite furred, and fades away quickly during newborn -> toddler, but never truly disappears. It's just quite subtle in most adults.
Hair thins out for both genders, rather than greying. (Grey hair is normal in some families.)
Names have a meaning. Family names don't so much. Names can change over time, but not often. (At least after adulthood.)

My family:
Based on blue-footed booby, but doesn't actually have blue feet/legs. It's common for my family to wear blue boots though.

Formal wear:
Women wear ribbons in their wings, the placement of which indicate a lot about their social standing, married state, and suchlike.
Men also wear ribbons in their wings, but the colour matters instead of the placement. (And tells similar things.)
The reason for these being different is so that a husband and wife can wear the same set of ribbons, while telling different things about them.
Actual clothing can vary a bit, but it's somewhat similar to human outfits.
Footwear is not supposed to be worn with formal clothing, but it's acceptable in most situations. (Only would be important in, eg. royal court.)