usually wear a cheap $40 black felt fedora - goes with everything and with the brim it keeps the sun out of my eyes and the rain or snow off my glasses if the clouds decide to open up.
fairly recent picture that is already in another thread:
I also wear one of those "driving cap" type of covers on occasion - tend to wear it backwards where it has that beret look if I do
and no worries about "hat hair" here, as I have not combed my hair since 1996 and it usually is shaved or very short if I get lazy for a spell. A comb just get used if my beard gets enough length on it.