When opening the Christmas decorations box this year, I noticed a little Santa hat that probably sat on a doll's head in years past. This year it looked perfect for the ukulele, so that's where it went.
And then I realized I couldn't stop there. We had an ukulele club Christmas party coming up.
I didn't think to start photographing the process until I was nearly done, but it isn't brain surgery and I'm sure you'll be able to adapt it to your own needs.
I eyeballed the hats into isosceles triangles, making them roughly 3" wide, which was the width of my headstock. I was using leftover knit fabric from the Santa hat I made last year, but it should be about the same whether you use fleece or felt or fake fur—anything that has a small amount of stretch to it. Running the warp of the fabric vertically from the peak to the center of the brim will help with the stretch (in other words, the selvedge should run parallel to the silver ruler, below).
A quarter-inch seam took the width down to where it would fit snugly.
All the trim was glued on. I used fabric adhesive because it gave me a little bit of extra control winding that feathery trim, but you could also use a glue gun or anything else that can attach fabric to fabric.
The final, and I think somewhat critical, step was gluing the tops down so that the hats could sit compactly on the headstock when the ukes were in playing position. I folded right over the seam and just added a dab of glue above the trim.
And here's the new, mass-produced version for my club friends. I actually like it a little better than the original due to the softer materials used.