I use a stick until I get the bow bending to the point where I can brace it. I've been told that there is no damage to the bow, in bending it to the braced position. After all, you leave the bow braced for hours right?
Use a 1x2 of some hardwood, about 30" long. Notch it every inch starting about 6" from the end. Notches should be at least 0.5" in, up to an inch. And angled enough so the string won't slip out (30 degrees). You'll need quite a few notches, maybe a dozen. Not that you are going to be bending the bow that far, but a long string stretches sometimes and you might need the extra notches to get the bow bending the 6" or so that will get you to a braceable state. Also, put a big notch in the end so the handle will stay in position, basically a smaller square cut in the end.
Hope this helps, if you need a pic I can see about posting one tonight but you probably get the idea.