I searched for patterns for creating your own diapers and I liked these two the best:
The first one is the one I actually used to make my diapers. The directions are clear and easy to follow, includes helpful photographs of every step, and doesn't require a serger. It also has elastic around the legs and back. I have six Kissaluvs contour diapers without elastic on the legs and they leak out the sides, so I wanted to make diapers with elastic on the legs.
Even though I didn't use the directions at the second site, it was helpful b/c it suggested using old t-shirts to make the diapers and gave a recommendation of 8 layers for the soaker in the middle of the diaper.