Not to give away my trade secrets, but I can say really the first thing you need is graph paper. I buy mine from Rite-Aid and its almost legal size. Take a sheet of graph paper, fold it in half. You can now begin to design your sporran. The key word is symmetrical, so you can take a plate, a compass, anything with curvature, and a ruler and design your own template which will be even on both sides and look awesome. Give it a shot-You'll see.