I don't have any pictures of the jig I use. I took a Call Blank and cross it with a pencil as turkeybuster showed above. Once this was done, I use a set of calipers and marked of the exact distance from center on each of the 8 lines. I then used a drill to drill all 8 of the outside holes. I drill out and glued a small dowel into the center hole. Once all of this was done, I mounted Dowel Centers in each of the holes. Once this process was complete I had a reuseable jig that would place a small dimple in the correct position consistently on every call blank. To do this you drill a small hole in the center of each call blank. Place the jig you made into the center hole (If you do not use a Center Hole, leave out the center dowel in the jig) and then either push it down by hand or tap it with a Wooden or Rubber Mallet. You will then have 8 dimple in the wood which you standard drill bit will follow. Hope this helps!
