Summarize the following:
When you get tired of moving your head back and forth, change up the direction. Rock your head one way then the other like you're trying to touch your ear to your shoulder. This can be a tough one to do fast, so it may be best to save it for slower, heavier interludes.  To avoid putting your neck in an unsafe position, make sure you swing your head down a little rather than straight across. Be careful not to jerk your head too hard in either direction. This is a good way to pull something. If you have a head full of flowing locks (is there anything more metal?), wait for the next big breakdown to whip it in a wide circle and let it fly. Your head will resemble a tangle of swirling serpents let loose from the underworld to wreak havoc and tickle the faces and necks of the unfortunate fans in your immediate vicinity.  Finish off your windmill with a quick head shake to reorient yourself before returning to a normal back-and-forth motion. Windmilling should be used somewhat sparingly to break up regular headbanging. Pulling it out too often can make you look more like a go-go dancer than a grindcore devotee. Standing in one place throughout the entire show is no fun. Try pacing back and forth, stomping in circles, or jumping up and down to the beat so the rest of your body can go as crazy as your head. If you're feeling spunky, hop into the mosh pit in front of the stage and let the dark power of metal flow through you.  Coordinate your headbanging carefully with your other movements. Otherwise, you may just look like you're throwing a temper tantrum or trying to get away from an angry bee. Watch out for flying fists, elbows, and other body parts in the pit. Things can get pretty hairy in there! Stick your index and little fingers straight out and tuck your middle and ring fingers under your thumb. Then, shoot your hand up in the air tall and proud for everyone to see. This will give you something to do with your arms other than just pushing sweaty metalheads out of your personal space. Horns are often used to celebrate after a face-melting solo or signal appreciation to the band between songs.

Summary:
Sway your head side to side. Try the windmill for added flair. Add some movement. Throw up the metal horns.