Here's what I did to make a good-ish Jazzmaster template.
1, find a pic of it on the net (must be a good photo, flat and straight on, not at an angle) and print it off - try Warmoth, they've got some pretty good images in teh bodies section fo their on-line catalogue.
Ifound a pic of the body i want to make
2, decide scale length you want (you could maybe half it for convenience).
lets say i want a normal scale of the neck for the bodie i want
3, Blow up the photo on a photocopier using A3 until the scale length of the photo matches your real-life scale length.
this is where i get confused
4, Copy the body area (will probably take a few sheets of A3 which you'll need to stick together
this i understand
5, You should then have a full size body shape which you can trace onto your template material and shape
and this i also understand