1. Cut out two rectangles (a front and back) wide enough on the short sides for all your hooks. I put two pockets on mine, one on top of the other, so this kept it from getting too wide. The height should be about 150 - 175% of the length of your tallest hook. (Mine is approx. 16" x 13.5") Cut out your pockets, the same width as your rectangle. The height of your back pocket should come up about 3/4 the length of your longer hooks (keep in mind you will hem the top and need seam allowance on the bottom, mine was 5.5") and the smaller top pocket about 1/2 the length of your shorter hooks (mine was 3"), if you want to add this pocket at all. You will also need a strap to tie your roll together once it's finished.
2. Hem the tops of both pockets, then use your hooks to figure out how wide you want your slots to be on the smaller pocket (approx. 1") and pin there. Sew the top pocket on to the back pocket along these lines. The plaid helped me keep my lines really straight.
3. Place the joined pockets onto your larger rectangle front, lining up the bottoms. (Ignore the excess plaid at the bottom because I decided my back pocket was too tall, 5.5" is what I cut it too). Sew down the same lines you sewed for the short pocket to attach the back pocket. In some places I skipped a line to make some bigger slots in the back pocket (2") for my big crochet hooks. I also left space at the ends, as shown in this picture by the folded back piece, for bigger things like rulers or scissors.
4. Make a strap or find an existing strap to tie your crochet hook roll together and attach it on the lower left-hand side of the large rectangle back piece. The exact measurements for where to put this depend on how large the roll is, but about 4" in from the long side and 4" up from the bottom worked for me. My strap is just under 2' long, but if you want to tie a bow, you'll need to make it longer.
6. Top stitch around the edges to close the gap and make it look nice and neat. Now you can put your hooks in it!