Use a drill guide block with a pre-drilled hole

Clamp a block of scrap wood with a pre-drilled hole onto your workpiece, then drill through the block's hole into the material below. The block's hole physically constrains the drill bit and prevents any lateral movement during the critical starting phase.

How to Do It

1. Take a scrap block of hardwood (maple, oak, or dense plywood) at least 3/4 inch thick
2. Using a drill press or very carefully with a hand drill, bore a hole through the block matching the exact diameter of the bit you plan to use on your workpiece
3. Place the guide block on your workpiece, aligning the hole directly over your marked drilling location
4. Clamp the block firmly to the workpiece (C-clamps or spring clamps)
5. Insert the drill bit through the guide block hole and drill into the workpiece
6. Remove the clamps and guide block when the hole is established to the desired depth

Why It Works

The rigid walls of the guide block hole surround the drill bit on all sides, making it physically impossible for the bit to wander laterally. This is the same principle used in industrial drill jigs and CNC fixtures. The block guides the bit for the first 3/4 inch of travel, which is more than enough for the bit to establish its own hole in the workpiece.

Tips

• Use hardwood for the guide block; softwood (pine) wears out after a few holes and the guide hole becomes oversized and sloppy
• The guide hole should be a close slip-fit with the drill bit -- tight enough to prevent movement but loose enough that the bit spins freely without binding
• Clamping is critical -- if the block shifts during drilling, the hole will be off-location
• Make guide blocks with several common hole sizes (1/8, 3/16, 1/4, 5/16, 3/8 inch) and label them for reuse
• For repeated identical holes (shelf pin holes, mounting patterns), a single multi-hole guide block serves as a permanent jig
• This method also prevents the bit from entering at an angle, solving both wandering and perpendicularity problems simultaneously
• Common mistake: not clamping the block, then having the bit grab and spin the block -- this can damage the workpiece and is a safety hazard