A messenger bag big enough for a tablet or laptop. First make a sleeve with something thicker (I use 2 flannels with a strip of batting at the bottom) to put the tablet in and then it is a removable insert for the bag. Make the bag in a darker brown or blue denim and make the lining something he does (sports, comic book heroes,cars, etc.). The bag is mostly straight sewing lines but has several good techniques to learn (straps, lining,pockets). This is one of the projects I would teach during my summer classes of girls and boys ages 10 - 17. There are many free patterns for messenger bags available online.