this only works in certain instances, but its very helpful...not sure if you could do this on a warrior, though
Basically, what you do, is right after combat is over, faerie fire a critter. This will put you and you only into combat, so youre rage will not degenerate. The critter will evade bug after awhile and run back to his starting position, so either find 2 critters and time it so one is running around when the other evade bugs, or use enrage during this so you dont lose hate. This is good if your trying to build hate for a boss also, as you can enrage up to 100 rage and then charge into the boss.