Recently I answered a question along the lines of "You look like you fell off the ugly tree, hit every branch on the way down, landed in a pile of ugly, and then got attacked by the ugly wolves. How did a woman ever go near your hideous, warped form?" To which I made reference to having an enormous penis, because that's what you do on the Internet, but I did offer a serious answer: skill, charm and wit.
Having been an active player and current close observer of the sport of dating for years now, one thing I've learned is that looks have almost nothing to do with how often you get somebody in the sack. For example, according to research, "overweight" women (the study was based on the outrageously broken BMI) lose their virginity at about the same time in life, have the same amount of sex, and the same number of partners. In fact, overweight women actually get laid slightly more than their skinnier counterparts, which has generally been chalked up to fat guys deciding they have a better chance with the pudgy sister instead of the cheerleader.
Beyond that, though, it's a matter of personality. People are naturally attracted to happy, funny, intelligent people because they make everybody feel good. Being good with a joke is the rippling six-pack abs or perfectly formed breasts of the mind; if you can make people laugh, they want to be near you. Then all you have to do is let the baser instincts take over, and they'll want you, period.
Similarly, if you can have an engaging conversation about shared interests, it's surprising how far that can take you into somebody's pants. I've never slept with a woman I couldn't at least have an interesting conversation with, mostly because that's how I met them in the first place. And that leads us into the final factor.
It doesn't matter how hot your partner is; if they're stupid, it's incredibly embarrassing. Very few of us can bone someone dumber than we are without feeling at least a little shame. Even a one-night stand is somebody you might see again, or run into at the worst possible moment. At best, you look shallow, and at worst, you look like the kind of person who resorts to fooling stupid people into sleeping with you. So, your choice is looking like you have a crappy personality, or that you're a borderline rapist.
So, if you "have a great personality", don't worry: it's really all you need to get as much action as you want.