Unsatisfied with commercial kitesurfing boards, I decided to make my own. I found the commercial boards to have too much rocker, too many fins, stupid graphics, and, worst of all, too high a price tag. With $50 worth of marine grade plywood you can build a board that will drop the jaws of all the board-shorts-on-the-outside-of-their-wetsuit types as you scream upwind.
Step 1: Design your board
I learned to kitesurf on a rectangular board, 16 x 60 inches. Nearly anything of this same approximate surface area will work. My current favorite board (which has lasted more than two years now) is a perfect oval 62 x 16 inches. The holes for the footstraps are set 1 inch forward of the centerline. My feet naturally sit about 22 inches apart, so I set the 7.5 inch wide footstraps 22 inches apart. I also put in a hole for a leash.
In this files section are two CAD files (DXF and Corel Draw) of my favorite board.
I printed my design out on a large format printer. You can also just draw your design my hand on a large sheet of paper.