First you'll need a merchandise table. It needs to be at least five feet long with folding legs and manned by someone honest, preferably one of your Presbyterian buddies. Make a Web site, or get one made. It's almost certain that one of your little siblings' nerdy friends knows HTML or Flash, so bribe him or her with beer. Spend the extra cash to get a .com or a .net—backslashes are so lame. Next, you'll need a genre. Predetermined categorization will save an enormous amount of time during your band's lifespan. When people ask you, "So, what does your band sound like?" you need to know what to say. Record executives and attractive people who come to concerts to get laid want a curt, decisive answer, preferably delivered with cool indifference. Also, when you get written about in zines, on message boards, newspapers, glossy and glossier magazines, and eventually Spin, people will need to know where to place your band on the giant musical continuum map they keep in their offices.
The easiest way to find a genre is to pay attention to what's popular, but not too popular. This method is risky in that it depends on precise timing. It's best to establish credibility in the incipient stages of a genre. Ideally you should be a part of the second or third wave of a certain genre, so you can maximize exposure before your audience is saturated with the genre. What constitutes a "wave"? A wave depends heavily on promotion cycles, album posters, number of choruses, CDs containing three minutes of music—things too esoteric and complicated to get into here.
Another method, one that depends less on current media-induced trends but may require you to expend more energy learning how to play your chosen instrument, is to unearth some musical movement that was never really popular (except with some snobby, idealistic elitists from Manhattan or some such place) or has been out of the general public consciousness for at least six months. Generally the more obscure the better, but this isn't always so. Recent examples include: guitar-based folk, prog and kraut-rock, no wave, new wave and Iron Maiden. But there are still billions of latent genres waiting patiently for rediscovery and recombination. A genre that relies heavily on electronics is always a safe choice. Bands with drum machines—or better, no percussion at all—are always better. The adage that drummers are flakes is the closest to being a tautology as a cliché can get.
Take your chosen genre, and combine it with some other genre that has more hooks and choruses or melodies. Most likely many people with dyed black hair, jean jackets, tight pants and studded belts will namedrop you nightly. These people like to pretend they don't have money, but their parents certainly do and they'll soak up your merchandise. Winning these people over is the first, crucial step in becoming a real band.
If these methods don't work, forming a cover band or bar circuit band (cover bands with different song titles and lyrics and safe, easily palatable melodies) are other options for success. These sorts of bands are almost always more successful with female vocalists, for obvious reasons.
Make sure the genre you choose has the outward appearance of danger, sexuality, deviance or legitimate anger. You are the rebel, you are the provocateur, you are angry at society and want to revolutionize it by being rich. Not interested in being rich or having many, many meat and cheese trays at your disposal? It's one of the hard truths of life, but you're not ready to be in a real band. You're a sucker and probably fit to install drywall or write poetry. If you can handle it, come up with a name, go buy some equipment and buttons and stickers and novelty items like shaving kits with the name on it and start kicking ass.