I have the girls buy 5/8th of yard - I need that much length for the full hat. Their choice. Then a nurse friend works in the other hospital and he drives over each week, so he is my currier. There are a few pieces that I thought were ugly, but most are wonderful.
No, I don't sew boy hats. I got a pattern from my anesthesia friend, bought him the fabric, and all ready to sew it, and he was killed in a plane crash that week, and I've never felt much like sewing them since then. All I would suggest is getting either a hat that the reps leave, or a paper hat, and make a pattern from that.