I made myself a hat!
I used the free Set Sail Hat from Patterns for Pirates. I made the biggest brim size but ended up trimming a few centimeters off and finishing with bias binding. The interfacing was some old stuff I had at home sand ended up being rather floppy so I added extra interfacing and lots of top stitching. It's still a little floppy so I might trim another couple of centimeters off and see if that helps. Probably would have been smart to just buy what was recommended...
Anyway I'm really happy with it, and even happier that I don't need to keep replacing my straw hats that never last long and can't be washed!