I have started saving the bottoms of tins for making templates of shapes I want to use. They are quite handy, and after a while you'll have a whole stack of possible shapes to help with the design process. They are especially handy to find just the right spot on the tin to cut, and will ensure that you end up with two pieces pretty much alike.
So here's how I go about it: first develop the shape you want; graph paper is a good tool for that. Trace the design onto tissue paper, then squeegee (popsicle stick or a bit of cardboard) a thin layer of rubber cement to the back of the tracing and stick it to the tin you plan to use for the template.Drill or punch a starter hole, and then cut out your shape. Then, with riffle files, debur and true up the shape. Now you have a very nice design tool. And you are using your cut tin all up, even the part that is not printed.
So, dear scoffers, I was able to get the detailed edges of these little Chinese lantern shapes, which I could never have gotten with snips. What you do is glue more tissue onto the tin you want to use, lay down the template and use it to trace the outline with a fine lead pencil. With practice, you can actually saw right in the pencil lines, and with a fine saw blade, it doesn't take much filing to clean it up.
The jeweler's saw frame, it's not just for silver any more.