That is a nice pattern that NiceNCLady told you about but you don't necessarily need to use grommets in the sides. I looked at an Under armour bag my son has and it has about a 3 in piece of webbing strap folded and sewed on the sides and you just run the cord thru it. This bag was small so I made him a bigger one out of that flag type nylon material and the nylon rope in sporting goods at Walmart. I also doubled the material so it would be sturdier. It washes really well. You know boys are messy. It made him a really nice bag. The rope was about 3/8 to 1/2 inch size. Probably 3/8.