A question for Sauron

Sauron is a completely evil being who wants to kill all foes and be the one ruler of Middle Earth.

So here's my question: Then what?  Let's say Sauron were successful (as we know from the books and films he is not) and killed everyone who resisted him, would not bow down to him.  What would he do then?  How would Sauron pass the time, if he had no one left to conquer?  Would he be able to say "I won, the war is over, now I can relax and listen to some music, write that novel, clean out my cupboards?"  Or would he still be forever on guard for possible resistance?  What would  his army of Orcs do if they had no one to fight?  They were created to be warriors.  What do warriors do when there is no war?  What do haters do when they've killed everything they hate? 

If course I'm not talking just about Sauron.