Hope this helps...I just learned after I used and re used a paper one someone sent me.(the last fold (pic4)) should be lined up,,it popped open when I took the pic
start with a circle(any size) I used a pizza pan
fold in half
fold in half again
and once more
line up ruler and cut from edge to edge
open up and there ya go!!! Make bigger or smaller by adding or subtracting from each side after you cut it...just use your ruler and cutter...