A dowel jig works well for this procedure. (See photo.) Drill two holes 3/8 x 1-3/8 inches deep, 5/8 inch from the front and ...

I would also highly recommend a dowel jig and/or dowel centers. When creating dowels, I like to align my boards by clamping them together with the sides that will eventually have the holes facing out.

The Rockler Corner Key Doweling Jig clamps to the corner of a box and guides an extended-length bit through the joint at a perfect 45° angle to the sides. The resulting holes allow users to add ...