There's an easy way for a simple light bulb-change to go wrong: You try to unscrew the burnt-out bulb, but it gets caught in the track wrong, or you accidentally pull too hard, and it breaks off in its socket. This is a really dumbfounding problem -- getting a piece of metal out of a socket with nothing to grab onto to twist it with -- much more so than a simple burned-out bulb was. Well, this is only a problem if you aren't clued in to our easy solution.
Grab a bar of soap, press it gently but firmly into the portion of the bulb remaining in the socket, and use it to unscrew the remnant. For safety's sake, you should cut the electrical power to the socket first.
Adapted from "101 Old-Time Country Household Hints," © 2008 Publications International, Ltd.