I've used chisel, sandpaper and sanding sticks (pioneered by Brian Gallop iirc). Chisels first, and only if a lot of material must come off, otherwise, sanding sticks to move fast, then the sandpaper strips (backed with clear tape for strength) to make the final fit.
Another tip to add to the above, mask off your body with low tack tape, or the pulling of the sandpaper will leave little scratches. I also use lacquer solvent along the edge of the heel and touch up markers (for furniture) to tone down any white wood exposed by the reset. Helps with a nice, clean looking heel/body joint.
BTW, don't forget to frequently check your E/e string alignment as you remove material.