I needed to enlarge a previously drilled hole. Since I couldn’t use my hole saw’s pilot bit to center the hole, and I didn't have my drill press with me, I had to come up with a solution. What worked for me was to connect two hole saws together. One was the size of the existing hole. This saw "guided" the other hole saw that was the size of the hole I needed to drill.
10 Creative Home Hacks That Will Improve Your Life
Here's an oldie with a twist. Use pieces of garden hose or other tubing to soften the jaws of slip-joint or other pliers so you can grip plated surfaces without damage. The twist? Size them so you can slide them up the handles to keep them handy.
Straight-Up Drill Guide - To bore a perfectly perpendicular hole, you need either a drill press or a couple of scraps of wood screwed together. The corner created by the scraps will steer the bit straight in every time. But if you’re looking for an excuse to buy a drill press, forget you ever saw this tip.