I was requested to make a messenger bag for school. Since I didn't want to go out and spend lots of money on fabric, yet I still needed it to be waterproof, I went thrift-store-shopping and found this large jacket:
I cut it up into bits, and removed the lining and laid out pattern pieces and tried different layouts until I was able to make everything fit. I must say I'm rather pleased with the results.
So, thankfully, is my son.