One way to save time when using the circuit tracker types of devices (one end plugs end, other device is a battery powered wand that beeps at the correct breaker), is to realize that the wand will also beep when you put it in front of another receptacle upstream on the same circuit. If the circuit branches upstream, it may or may not detect the branch. You can even sometimes find out where in the wall the wires have been run too. My goal was to map the entire house down to the wire. This helped a lot to narrow things down quickly, but I still had to open each box to make sure the number of cables made sense.
Works until the wife decides to clean all the cover plates and puts them back on without regard to what number went where. Then you're worse off because the lables are wrong!
-- Mark Kent, WA