I use to wear a Bill's on my soldier because I wanted a kind of General style to my soldier so I used a Dark Green Bills (about them same as bills actual hat), The Fancy dress Uniform and a Vigilant Pin.
I found a Honchos headgear a few days ago and replaced the bills with that though.
But yea I try to go with some form of Theme with all my classes (Parkour scout, French Officer spy, Parade Sniper, Biker heavy) so they actually feel interesting and aren't just a massive splotch of bright pink and black everywhere.