If there's a "craft" I haven't done that I really want to do, it would have to be the lost wax process of making jewelry and 3d objects. I was browsing for some tutorials and found this really awesome on on Instructables. This guy went and carved his own engagement ring out of wax, and had a jeweler do the final casting in white gold and setting in beautiful human-cultured precious stones (without all the conflicts!).

Check it out!