How to Drill a Clean Hole

I frequently need to drill a large hole through wood and I don't like the "tear out" around the exit hole.   I know it helps to have two pieces of wood together and drill through the first into the second (called using a sacrificial block of wood), but it isn't perfect, and sometimes its very dificult to use a sacrificial block.   I came upon this technique while doing counter bores, and will now pass it on to you.    

I measured the location of the two 3/8" holes on the front side and drilled pilot holes completely through the piece.

Here you can see the two pilot holes on the back side of the piece.

Now, using the pilot holes, I drill a shallow hole (like a counter bore) on the back side with the 3/8" drill bit.

Both back side shallow holes drilled.

Now from the front side, using the pilot holes, I drill completely through into the shallow holes I drilled on the back, the back side is as clean as the front.   Voilla, two perfect holes with no "tear out" around the holes on either side.

Closer look at two clean holes in a solid piece of wood.

1/16" pilot hole at center of desired hole.   This is 3/167quot; plywood.

Bore part way through on one side.

Drill completely through from the other side.   Now we have a clean hole.

Close look at front and back of the hole.