Dowels have been used for centuries, much longer than nails and screws. Factory dowelling jigs have metal sleeves that guide the drill bit, but you can make one out of a small block of hardwood that works the same way. It takes less than an hour to build several of these to fit all the popular dowel sizes.
Lay the block of wood on its side lengthwise so that you are looking at the end grain. Measure over from each end 3/4 inch and make a mark.
Measure down and make a mark intersecting the first mark at 3/8 inch. You should be looking at two marks centred on the end grain, 3/4 inch from each end.
Insert the Forstner bit into the drill press. Drill down through the block on both marks.
Run a bead of glue along the side of the block. Align it flush with the edge of the plywood and clamp it there with the hand clamp. Let it dry for one hour.
Lay the plywood portion of the jig on the edge or end of any piece of wood. Slide the jig over until the two holes in the jig touch the edge of the wood. Place a clamp on the plywood, securing it to the edge of the wood. Using the holes to guide your bit, drill the holes for dowels.
Always wear safety glasses when working with wood.