I probably took this further than most would, but I am planning on making multiple, swapable panels so I made my template out of 1/4" 5 ply birch plywood. I designed my layout in AutoCAD, printed it out full size and then transfered it to the plywood with a pin. I cut the template out on my bandsaw and drilled the holes. Then I attached it to a piece of 5/8" MDF rough cut to size, and on my router table I routed the panel to size and routed the holes using a flush cutting bit.