1. Be aware of what your body is saying. We all speak with body language, and you don't have to actually say anything to communicate a message to others. Unfortunately, your body may not always say what you want it to. If your gestures and posture are saying "I'm too busy", "Leave me alone," it's not likely people will approach you. Other people watch your body for cues, so it's important to pay attention to what cues you're displaying.
2. Open up. When people are uncomfortable in a situation they have a tendency to display closed body language. Examples include folding your arms in front of you, hunching over, and positioning your body so that you're angled away from others. These signals imply that you'd rather be left alone. If you'd rather not be left alone, make sure you're displaying open body language by angling yourself toward other people, sitting or standing with an upright (but not stiff) posture, and uncrossing your arms.
3. Use your eyes. Your eyes are not only your window to the world, they're also other people's window into you. If you bury your head in a book, stare at the floor, or look up at the ceiling, you close that window. This is all well and good if you don't want to be bothered on your commute to work, but if you want to look friendly and approachable, scan your environment with your eyes, and don't be afraid to make eye contact with people.
4. Smile. A warm, inviting smile can put anyone at ease, and it also makes you look like you're having a great time, which makes people want to be around you and get in on the fun. If you catch someone's eye, be sure to give a little smile, and be sure to smile often during small talk. It lets people know you appreciate talking to them. Smile with your eyes. When you do make eye contact, don't stare or glare. Instead, soften your eye expression and make your eyes "smile" or "twinkle" to show that you're friendly and interested in talking to the other person. If you're not sure how to smile with your eyes, get in front of a mirror and practice smiling without using your mouth. The eyes are actually more important than the mouth to what most people consider a "genuine" smile.
5. Beware self-comfort gestures. Nervousness manifests itself in body language in many ways. It's okay to feel nervous, but if you really want to socialize and meet people you should be careful not to appear nervous. Touching your hand to your face, especially putting it over your mouth, or, if you have a drink, holding your glass by your mouth can give people the impression that you're not interested in talking to them. Metronomic gestures, such as foot tapping, can signal impatience or boredom, so people may think you don't have time to talk or aren't interested in conversation. Other nervous habits — picking at your cuticles or biting your fingernails for instance — can also make you appear distant or lost in thought. Once again, just pay attention to what your body is saying, and you can avoid putting up these barriers.
6. Approach others. If people aren't approaching you, why not go to them? Nothing makes you look more outgoing and approachable than actively seeking out people and talking to them. If you're in an environment where you don't know anybody, the longer you wait alone, the more uncomfortable you're bound to feel. See How to Talk to Strangers.
7. Address any deeper issues. Your body language usually communicates your deepest emotions at any given time, and it's not easy to fake body language. The best way to look approachable, then, is to actually enjoy yourself in social interactions. If you feel anxious in social settings, or if you're uncomfortable around the opposite gender, get over your anxiety by seeking out opportunities to interact with people. If you have especially strong social anxiety (a common condition), you may find it helpful to seek out counseling or talk to your doctor.
