Chess is a very complicated game, as we all know. One of the reasons that it is very complicated is that you must move a piece every move. This makes it nearly impossible to hold the wonderful defense that you have created without giving your opponent an opportunity to penetrate your defensive scheme. This defensive structure that you have carefully crafted grows to be even more important in the end game.
Understanding that it is sometimes better to shuffle a piece back and forth from square to square, than to weaken your defense, is very important. Doing this may seem... boring... but it is better to be boring than to throw away a win or a chance at a draw. If your opponent allows you to do this enough, the game will end in a draw due to the 50-move rule. More often though, your opponent will grow impatient and make an error. This is assuming that you are in a weaker position and that your opponent is looking for a way to place you into a checkmate instead of letting you get the draw.
This frantic moving and searching by your opponent will frequently result in them making a mistake and giving you the victory. Another consideration is whether or not you are playing a timed game. If so, you can run your opponent out of time with this shuffling of your piece because your opponent will spend time looking for a mate while you are in a perfectly defended position that requires no thought. Look at your end game for opportunities to utilize this do nothing strategy. This strategy will come in handy at times and can help you secure a draw, or even better a win.