My SO and I got married this past July (7/11, hurrr), and it was a 3-day thing with a Friday BBQ, Saturday Ceremony, and Sunday Brunch. The BBQ was the most casual and offered the most potential for being outrageously whimsical/fun, so I made us top hats that fit our personalities and were appropriate for a Southern/German BBQ even if it was in a tongue-in-cheek sort of way.
I made my hat from a $2 4th of July cardboard top hat which was layered with tons of felt, ribbon, piping, netting/tulle, and just about everything. There are buttons, papier mache ladybugs, fake flowers, feathers, etc. A lot of it was working with the ribbon and netting/tulle. If it was red and/or white and fit within a Southern BBQ theme, it went on there.
My SO saw it and initially said he didn't want one but changed his mind a few days later only he wanted it "manly". I manned it up with some of the most manly stuff I could find - I found a lot of it in the dollhouse miniatures and leather working sections in Hobby Lobby.
Unfortunately, his head is too big for any premade top hat I could find, so I had to make it which was HORRIBLE! I made it out of artist backer board (I think that's what it was) and made it in 3 pieces: a tube, a brim, and a circle. It was a matter of easing, cutting, gluing, and forming. I'd never made a hat before then, and online resources were no help because it had to be sturdy enough to hold all the fun stuff.
To put his hat a little into context, he's originally from upstate NY, and we live in TX. He loves military stuff - you can see a mini mock-up of "Raising the Flag on Iwo Jima". He's also a child of the 80s. The hat is some sort of combobulation of toys (e.g., toy soldiers), Texas (e.g., the yellow rose of Texas), New York (e.g., apple), and guns (e.g., miniatures).
Construction was very time consuming and required multiple trips to craft stores. Everyone at the wedding loved the hats and thought they were funny. The BBQ was not meant to be serious in any sort of way, and I think the hats helped. Besides we're not very traditional..