Buzz your hair or let grow it out on its own accord. Don't get stylized hair cuts. Don't use hair products. Don't shave those dumb little lines into the side of your head. Run a comb through it if you must, but leave it at that.
All of the people lamenting the fall of masculinity in this country walk around with prim and proper little "hair styles," blissfully unaware of the irony. They might as well open a beauty salon.