Peg cheek shape.
Peg cheek shape is easily done, first make a holder for the peg as in the image then trim off excess wood on a band saw or with a coping saw. To finish the peg cheek use a drum type, sanding tool found in most hardware stores. If you have a shop vacuum tie the hose to the drill press table to remove dust. If you don't have a drill press a hand held electric drill mounted on a table will also work. If you have neither use a rasp to form the cheek.