http://www.popularwoodworking.com/features/fea.asp?id=1059
I didn't delve very deeply into this article, as I don't need a
dovetai jig, so I don't know just how useful it will be for making your
own dovetail jig. So, you're on your own.
JOAT
You only need two tools: WD-40, and duct tape. If it doesn't move and
it should, use WD-40. If it moves and shouldn't, use the tape.