Quick and Easy Probes
You may already have a favorite (non-electronic) probe for locating your targets but in case you dont or you would like a few spares laying around, here is a quick and easy way to make one that has proven to work great.
I prefer to use brass brazing rod for the shaft to help gaurd against scratching the targets since the brass is usually softer than most targets but that may not be as readily available for everyone. If you dont have a source for this, another rod that I have used is a piece of coat-hanger. The metal is usually farely soft.
Next I take an old broomstick, or two-by-two, just about anything that would make a good handle and cut it to about 4 in length.
Drill a hole in one end so the rod fits snuggly, press the rod in. Use sand paper or a grinder to round the end of the rod and your ready to probe!