If, by accident, I drill a hole too small with a hole saw, I take cardboard or a similar material and drill a bigger hole in it for a guide. Then I hold it over the existing smaller hole to guide a new start, and then I cut the material to the new, correct size.
If you ever have a Tapcon strip out in masonry wall or a screw-in panel cover or metal box strip out, insert a plastic tie into the hole and reinsert the screw. It works for me every time.
Cape Coral, Fla.
Oldie but goodie
Attracting the mess
When I was drilling into electrical panels with delicate, printed circuit boards, I noticed that metal chips pose a serious issue because they fall into the circuit board. I carefully use a round magnet with a 11/8-in. hole in the middle. Then, all the metal shavings attach to the magnet, not allowing any shavings to fall into the panel. Magnets from old speakers work great for this purpose.