I use basically the same method as John. I made a foam ball sander out of a 1/4" bolt and a mouse pad, duct tape, and velcro for a sanding disk. But that's only for the HF's that you can get a hand in. All the others I just take a good finish cut, and only sand as far as a finger will allow anyone to reach in. The ball sander has a couple other uses as well, and costs almost nothing to make. And john, someone gave me a bunch of foam for whatever reason, and it's just the right stiffness to make my own foam backed sanding pads. Made a 5" and 3" last night, they work great. I think that was you I had that conversation with not toooo long ago, haha. It's amazing how the foam allows you to keep the contours of the forms, and never dig in at all.