Using a self centering dowel jig
I bought one of those "self centering dowel jigs". The jig has two holes, 3/4" apart for drill guide bushings. It comes with two bushings each for 3/8", 5/16", and 1/4" drills. The jig also has two more holes without bushings, one for a 1/2" drill, the other for a 7/16" drill. You can find this jig by searching for "Self centering dowel jig" on Lee Valley Tools, Rockler, Woodcraft, or Amazon.
I have always been skeptical about guiding a drill by turning it inside a metal guide bushing. But all the drilling jigs out there seem to rely on this sort of technique, so I guess it's durable enough. I have only used this jig fora few projects, so I can't say how long it will last. I periodically put a drop of oil in the holes, in the hope that it will help lubricate the drill and slow down wear.
I have used the dowel jig for several projects, just click on the links below.
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