We're going to take a bit of 22 gauge metal (the thinnest steel I could get at OSH) and cut a pattern into it and then cut it out. Then we'll bend it around a convenient cylinder (a soda can is pretty convenient).
I made it at Techshop! www.techshop.ws
Step 1: Sizing the Metal
If you want to wrap something around a cylinder you need to get the circumference of the cylinder. You can just measure the diameter of the cylinder and then the famous formula C=pi*r^2 (circumference equals pi times the radius squared) (remember that the radius is 1/2 the diameter). But I find it difficult to get the measurement across the exact center.
Instead, I got some tape and rolled it around the outside with the sticky side out. I stuck it to itself and cut off the excess. Then I pulled it off, cut it, put it on a piece of paper and measured it.
You can also just use a cloth measuring tape. (So much simpler *if* you have one!)
However you do it add some space because you can't bend metal around the cylinder as tightly as you can bend cloth or tape around it. I added 1/2" but that wasn't quite enough so try 1".
Step 2: Patterns
It turns out that this isn't a very good pattern for cutting out of metal (it worked well for paper). But it further turns out that it COULD be great, even better than a more sensible pattern. But I'll go into that in the next step.
I've included the Coreldraw files in case you want to just use this or modify it.
Of course, you'll want to develop your own patterns but looking at my leaves might be instructive.