Rule one: Don't improvise material that sounds School of Cocker (as doubtless you will be tempted to do when a Pulp record, or similar, hits the turntable). There are lyric sheets provided. Learn them. Lip-synch. The aim is to be as shamelessly faithful to the original as possible.
Rule two: Same applies to the movements, which are just as, if not more important than the words. Always bear in mind, of course, that you will only succeed as long as you don't try to become Jarvis. Remember to save the last vestige of you for later - you are striving to be able to hint at the Jarvis Cocker you might have been had fate dealt you a different card.
Rule three: For this reason, you don't need to buy viridian shirts with aeronautically challenged collars, lederhosen or brown sauce suits (no really, you shouldn't have bothered. On second thoughts, a dash of mascara would work wonders.)
Rule four: There are no rules, only guidelines, which can be sub-divided into different "looks". The word "dance" shouldn't feel like a restriction - some may prefer "prance" or, quite simply, "stance".
l The "I seem to have left an important part of my brain somewhere in a field in Hampshire" look is an essential opener and closer. Keep the eyes blank and frown as though you were trying to remember something painful that happened long ago. Lids can seal up at times like Bryan Ferry or a newborn pup. At certain points, you can place your hands on either side of your head (range: hangover pout to eyes gazing aloft). You will also need the:
l Hands of a mime artist These should always be on the go, building and destroying unfeasible architectural projects. There's standard accusatory pointing (index and middle finger), vicar's teacup (little finger aloft) plus hypnotic clockwise and anti-clockwise motions, with a touch of the DTs. Once things really get out of hand, you will need Sheffield Semaphore: enact the twitching of net curtains, the opening of wardrobes, or imagine things rushing towards you which you fling violently out of the way (with a vigorous elbow shove). The main point is to create a scenario in which it seems plausible to adopt "the fan".
l Jarvis Cocker's "fan" has evolved from fringe-flicking to something that, at first glance, resembles a spider suspended over his forelock. It is, in fact, an upside-down fan (right hand pointing down, palm facing out, thumb at right angles) which is quickly snapped up and thrown away in anguish.
l "Daddy long-legs" For the rest of the body, just think of the kid at school who couldn't play games, perhaps yourself. Always stand near very inert people. Asymmetry is all: jerk your shoulders alternately; wobble at the knee; cross one leg over the other; even drag it along in a sidewards motion, as though it were paralysed. Jumps should be attempted. Unfortunately, the grander the gesture (eg crotch-grabbing) the more likely it is to be:
l Parodic When in doubt, keep eyebrows arched and wait for:
l Cocker climaxes (about five a song). First put your hands on your hips. Then shift your body weight (preferably negligible) on to your left leg, swivel your hips, and point your right arm either onwards or upwards (limp wrist optional). Attitude: "We can laugh about it now."
l It Your androgynous aura may confuse others. If you are asked to leave, then you've scored (metaphysically, that is). Bear in mind that, throughout history, non-believers have felt threatened by disciples. Repeat the words of JC ("We Shall Prevail") to fade.