If you are not confident with your naked body, none of your clients will be, and you'll make no money. Also, you'll be shy and miserable all night. You might as well get an office job.
Despite what you think, you don't need to look like a Playboy model. (And, actually, Playboy models come in all shapes and sizes, too).
One rule is that you DEFINITELY need to be toned -- no cellulite, no jiggling stomach, no love handles, no saggy butt. One thing all good strippers have in common? A waist that tapers in tauntly in the middle. So diet and exercise.
But after that, it doesn't matter if you are tall or short, petite or leggy, busty or small-chested, voluptuous or boyish. You can't change your genes (well, you can get surgery -- more on that later) so don't worry if you didn't win the stripper DNA lottery.
Different men have different tastes, and you should be proud of what you have.
Look at Kiko Wu, one of my favorite stripper-bloggers. She is short and reasonably small chested, but she is one sexy lady. Now, she's not going to snag a client looking for Marilyn Monroe, but she will get the ones with yellow fever.
As long as you are in good shape and are well groomed -- nails, hair, clothes, make-up -- strut tall. And if anyone gives you abuse about your looks, just calmly and politely back off.