Step 1: What you Need
1 black sharpie
1 Large safety pin
UPDATE: After wearing this costume for about 8 hours straight, I recommend forgoing the velcro and using one giant safety pin on the outer layer. The velcro was fine for just standing around, but when truly put through the paces, the velcro wasn't robust enough. I put a large safety pin through the outermost two layers and it worked all the rest of the night.
Step 3: Roll it up and velcro it
UPDATE: Skip the velcro and save yourself some money. Use a large safety pin on the outermost two layers. The ones used for baby diapers are large and sturdy enough for the job.