This is the front. I added an initial to personlize it. I added some sew in interfacing (aka a layer of some spare flannel and canvas) and quilted it (with my new walking foot!) to add some sturdiness to the cover. I made a crayon portfolio before with canvas for the outside and cotton for the lining without any interfacing before but found it to be too flimsey looking.
Instead of doing a velcro enclosure, which I wasn't sure would keep things from falling out, I used a thick elastic that wrapped around to the back, as shown above.
Here's the inside (sorry, don't know why this pic turned out so horrible even though I took it at the same time with the same lighting), I made bigger gussetted pockets on the left for cars or other little toys and smaller gussetted pockets on the right for crayons with a pocket to hold a notepad in the middle. I made it more complicated than the tutorials I've seen but I didn't want flat (non-gussetted) pockets because the cover would show bumps/bulges once you put anything in the pockets. I had originally planned to add an extra flap to cover the crayons so that any fabric marked by the crayons would be hidden, but I was running out of time so I left that out.
I'm really happy with how it turned out and will need to make one for my little guy too (except with the extra flap to cover the crayons).