I drew a pattern with a red pen then refined it with a black pen. After getting a pattern I liked I flipped it over and marked it heavily with an HB pencil in preparation of transfering it to the wood.
I then flip it back over, lay it onto the wood, and retrace the picture pressing hard to transfer the image to the wood.
If you're not real good at making a pattern but find a good printable picture then all is not lost. download the picture and in an edit program (such as Paint, or Photoshop) flip the picture to a mirror image and adjust the size til it prints the image to the full size you what. Print it on a laser printer or copy it on a laser copier. Don't use a color jet type, because we want the waxy hard ink produced by the laser print/copy process to use in our transfer. Take this printout and lay it face down on the wood and use a hot iron to melt the ink onto the wood.