Table saw. I wrap the cut line with a couple layers of masking take. Level the stock on the table with cardboard shims, push the butt snugly against the fence and slowly, carefully feed the stock thru the saw blade.
If done carefully with a sharp, fine toothed blade you should only need to hand sand a bit to clean it up. To sand it, hold the stock vertical and sand back and forth on a sheet of sandpaper on a flat, smooth bench top. Last step, peel off the tape and tell yourself what a great joiner you are!