[Gaffboat]

I would cut a pattern out of 1/2" mdf or plywood to use with a pattern bit in the router. You could use your jig saw to cut the pattern by cutting about 1/8" outside the line of your drawing and then sanding to the line to make sure you have a smooth edge. Cut your final pieces the same way (leaving the 1/8" excess) and then use the pattern you made to rout them to final size. The bearing on the pattern bit follows the curve of your pattern to give you a smooth, accurate final shape.

 

[Gaffboat]

Just in case you didn't understand what the other guys said. Same thing, just a video. Spotted this the other day, similar to how I do it, except I keep my templates/patterns/masters for use again later, mine are two layers of 1/2" plywood, also I hold the work in place with nails instead of double-sided tape.
Easy peasy.

Good video, Theo. That explains it better than my description and should be helpful for Horacio.