This is going to sound ugly, but I don't mean for it to. When I started carving and tooling my biggest fear was the OAK LEAF, and it did not matter which one. . . . . I got out and dusted off my old Boy Scout Manual and looked up leaves, then I bought a basic forestry book with many pictures of more leaves. I started drawing them over and over until the basic form was almost second nature. Then came the carving, again over and over on scraps. A single leaf, leaves stacked on leaves, etc. I found that the more time I took to actually look at leaves it finally sank in. Now leaves are just another scratch on a piece of leather. Tandy has several books/manuals on leather tooling that covers leaves you might want to look at. Hope I was able to help even if just a little. Good luck