Have a couple of projects that would look better with mitered ends rather than a butt joint. Question- how is the best and most accurate way to measure for the wood to join perfectly at each corner? One will be a display for pen boxes- bottom is 1/4 plywood and the sides will be 1x2 pine. Basically a tray to fit eight pen boxes (Hobby Lobby) for display at a museum...if the jury approves the pens. Thanks.