Combating dull, flat hair!?

Hey, i'm a guy with kinda shortish hair, i was wondering on how to make my hair look more awake and flowing if that makes sense? haha! i find that after i wash my hair it goes really fluffly and looks kinda dull and, well... not dead but unhealthy. i don't condition my hair as i was told only girls condition their hair because they usually have long hair? is this the case or should i start conditioning my hair? if so how many times a week? are their any products i could use on my hair to waken it up?