The kind of stuff to have in my room?

ok so im decorating my room and im a teen guy, who does taekwondoe, and is in love with music (mostly foo fighters, red hot chili peppers and relient k). jw what kinda stuff could i put up on my walls or what not without seeming too girlyish or weird? i was thinking of putting a red hot poster up but is that too girly or what?