About a month and a half to two months before hand, you start looking for a date. If it's the senior prom, better make that three months. In general, the more desirable members of the opposite sex will find dates sooner rather than later. It's a good idea to have a number of people in mind, just in case. Most people will sooner not go than go without a date if the atmosphere at your high school is stuffy enough.
Make sure you are of the appropriate gender before extending an invitation to the dance. For some dances it is customary for guys to ask girls, for others it's the other way around. This custom may be disregarded in some social circles, but it may be closely adhered to in most. Depending upon your high school and the formality of the event, it may be common courtesy to actually extend an invitation to your prospective date at least a month before the dance. This will leave time to organize such things as dinner plans, funds, acquiring the proper attire, transportation, picture taking, plans for after the dance, and time to ask some one else if necessary.
If you are being asked to a dance, barring extenuating circumstances, it is always honorable to accept the invitation of the first person who extends one to you.
Also, it may be a good idea to go on an informal date before the night of the dance in the case that you've invited some one who you don't know very well. Furthermore, pay close attention to how your peers pair up. If you see trouble in the making, keep your distance, or try to reconcile differences up until, but not during, the dance. Getting there is half the fun.
Unless there is some pre-existing relationship between you and your date, do not go to the dance expecting some fantastic romance to develop. It's not that you shouldn't pursue such things if the opportunity presents itself (indeed, it is fun to be pleasantly surprised), it just sucks a lot more to be let down if things don't go quite as you would have liked.
At the dance, relax and have a good time. Be courteous, kind, calm, collected, and mindful of your perhaps new and expensive clothing unless you're dancing, in which case a disregard for your own appearance is encouraged. If you can't dance, fake it, and then make fun of yourself later. This particular approach can work wonders. Be sure to visit a while with each of your friends. If you notice a friend getting along well with his/her date, congratulate him/her and wish him luck. Being happy and sociable in such a festive environment can strengthen the bonds between you and the people who are important to you. In the same light, being negative and depressed, no matter the cause, can cause people to feel sorry for you, or even resent you for whatever reason. Try to keep public displays of affection to a minimum. Holding hands, and a kiss here and there should be acceptable, but slobbering and groping are usually frowned upon. Use your better judgment.
As a final note, do not ditch your date. Ever. For any reason. It sucks to get ditched, and it sucks even more to face the wrath of the person you ditched if they decide to exact revenge.
The emphasis here seems to be
planning, however,
winging-it,
playing it by ear, and being
spur of the moment can also be
charming to your date, exciting, and
fun.