Stay true to yourself. Even though it's tempting to write rhymes like Eminem or have a flow like the Notorious B.I.G., the only way you'll really become great is if you find your inner voice and stick with it.
Deliver an energetic, enthusiastic and passionate performance each time you hit the stage or battle another rapper. Great rappers like Tupac and Jay-Z are keyed up every time they hit the mic.
Spend time refining your rhymes off-stage. Once you've written a song, read through it every few days and look for ways to improve its flow and edge.
Get the crowd involved with your performance. Having them chant the chorus or repeat certain lines of your song is a fantastic way to energize your performance and build your reputation as a virtuoso emcee.
Watch as many live performances of other rap artists as you can. If they're legends like Snoop Dogg or Ludacris, study their delivery and learn from their skills. If they're just regular rappers, critique their performances and think of ways you'd improve upon them.
Wear gear during your show that's appropriate for your style of rap. Not every rapper needs an iced-out chain or a multicolor jacket. Dress comfortably, and let your performance speak for itself.