You can shape plywood high power rocket fins by hand, even without power tools. It's easy - though a little time-consuming.
In this video, I'm turning my Estes Leviathan fins into airfoils with a simple hand sander. Some people feel that airfoiled fins reduce drag and allow a rocket to fly higher. Others suggest that the benefits are pretty minimal.
Either way, I like the way it looks, so I'll often do it.
I start by marking where I want to sand, using a ruler and a tool called a sewing gauge. I bevel the leading edge just slightly, then round it with the sanding block.
Then, I bevel the trailing edge, and get it much closer to a "knife's edge." I don't go all the way, though, because you can damage the edge of the fin with the sanding block if it gets too thin, and even if that turns out okay, a hard landing may cause the fin edge to chip off.
