I found this pattern/tutorial by lupinbunny.
I made a few mistakes, and a few modifications. I'm still a little confused about what I did differently than the pattern, but somehow it seems different. Though all in all it turned out well. I added the fourth pocket with velcro closures. and I taught myself a little crochet so I could make the strap closure. I made the big white button out of sculpey. It was a pretty fun project, I haven't had a real sewing project in a long time.
A few things I would do differently if I was going to do it again: make it wider, make more wide pockets, make the two lower pockets shorter, make the velcro pockets deeper, make the fold over flap longer. Oh, and I would NOT use cheap pink chalk to mark lines with. I really had to scrub to get it to come off, and then my needle roll took FOREVER to dry!