What to do in a bad endgame?

Here I want to post some thoughts on one of my recent games played within the Team Europe 2010 tournament here at chess.com. My opponent (pretty much lower in rating) was playing black and he played well enough to enter into an endgame where I had a great deal of chance to lose. However, I managed to fork his rook and finally to win.

But this is not the point. The main thing is the lesson I've learned: if you are inferior in the endgame, don't be hurry to resign. Set a clear defensive goal, create a plan and resist as long as you can!

Here is my resistance strategy in the game: restrict the mobility of my opponent's doubled rooks and wait for a chance to fork him.

You might say, the guy was well behind in rating but firstly: this does not mean anything cause with low rating you have nothing to lose, and secondly: this does not affect this rule of endgame I tried to illustrate:

in an inferior endgame position, even if you are clearly losing - restrict the freedom of your opponent as much as possible and wait for his mistake