"Staple karting techniques like a rocket start are in, triggered here by revving up before the lights go out, letting go of accelerate and then hitting the gas the moment the race starts." --- Artiste of the Slightly Funny Deal
Actually, revving before the lights go green doesn't do anything. The rocket start is triggered by stepping on the gas the moment the startlight turns green.
Also it's much easier to just hit the gas the moment you see the AI's rocket start flashes; I use this method and never failed once (which is crucial for the latter half of events; every AI driver WILL rocket start without fail)