I square up a block and then cut them out on the bandsaw, which leaves one "clean" side. I have a jig that is nothing more then a block (from laminated plywood) cut on my desired taper with a stop block on the end that is shorter then the wedge. I then run this through my dimensional drum sander. The wedge comes out nice and square, feathered, and ready to glue up. Before I had the demensional drum sander I used a drum sander for the drill press that has the bearing guide on the bottom. Made a similar jig only oriented on it's side. The drum just has to be large enough that you have a square face over the surface of the wedge.