So I've started making some jigs to help me make a guitar. I just finish what was probably my most complicated jig.
First, I had to make a circular piece (the dish). Then I made a table thing that the dish could rest on, with a dowel in the middle so that I could turn it. Finally I made a sled that just barely sits on top of the dish with rails that lower down in a subtle radius. I took the router and slid it along in order to make the radius. You can see I'm about halfway done at this point.
As you can see, it made quite a mess, both on me and everywhere else.
The radius dish helps me slightly dome the top and bottom of the guitar.