This was a quick project I did for my daughter.  I cut the back and front pocket areas from an old pair of jeans and sewed them together, added a quick lining with a pocket in it and a shoulder strap.  I thought she would decorate it all up with stuff, but she liked it with just the crystals around the pockets.  It is very handy with all the outside pockets for cell phone, keys, etc.  I am going to make one for myself.  You can customize them anyway you wish.