The most amazing and detailed tutorials you will ever find on How to make any kind of bag! bag pattern charts use the basic design and look through this board for designs or let your imagination run riot
This would be a good idea for a men's shirt refashion. Customize the neck opening after cutting the collar off. Leave the sleeve cuffs on, or cut to length, or whatever length you want, or go sleeveless. Nip in the waist with elastic or darts.