Lower 1/4 panels

Ok I am about to get ready to work on my lower 1/4's on my 66 Dart, Was thinking about just doing fiberglass, but now am thinking about making my own patch panels. Ok, never have done this before, but am thinking it would be a better way to go. so what are some of the things I need to do to do this. I already have the welder so that's not a problem. And have a friend who has a roller for forming the metal to the shape I need. Just looking for some pointers on doing this