1. Start with a moody voice over on top of some gritty scenes of 'the streets'. This is not merely the only chance you will have to display any sense of realism it will also effectively dispense with any need for plot or characterisation for at least the first hour of the movie, thus enabling it to become little more than a glorified rap video.
2. Indisperse dialogue with long dance sequences, ideally when least expected. The more complex, tightly choreographed and improbable the better. Ridiculous masks are good. Oh and turn on the fake rain anytime anyone so much as thinks about dancing outside. Assuming by 'anyone' you mean a hot chick in a white top.
3. Hot boys onscreen longer than two minutes are required to take their shirts off. Unless they are supposed to be evil.
4. Hot girls (read: every flipping girl in the movie, unless she is supposed to be evil) onscreen are required to a) tear the lower half of her top off, b) wear a gravity defying push-up bra, c) spontaneously decide to wear a hat half over her eyes in order to allow her dance double to step in for the trickier dance sequences.
5. If the studio REALLY requires the main character's love interest to be played by a blonde-haired blue-eyed boy so bland he may as well be a mop in a funny hat do be sure to wedge a full blown hottie into another part of the movie, ostensibly as an arsehole-with-a-secret-heart-of-gold but really so the rest of us can imagine him tearing his short open in the fake rain while back-up dancers straddle his torso.
6. Make Step Up 3. Please.