From a psychological perspective, qualify other people before they qualify you: If you see a cute girl, ask yourself "Why should I like her?" instead of "why should she like me?" Basically shift the focus off you, onto them, to prevent yourself from being too self-conscious or wondering what they think of you. I also heard "Be interested rather than interesting" meaning ask questions, find out what makes someone tick, and reinforce that you're listening by rephrasing what the person just told you and saying it back to them. Remember, people love to talk about themselves. Get them talking and listen well, and that again shifts the spotlight off you. Also like others have said, have a passion or something you do well. Doesn't have to be fancy, try something simple like knowing how to pick a wine, grill a perfect steak, know some great little restaurants in your city, etc. Basically have something to share. Are you looking for confidence in general, or with women, etc? What exactly are you insecure about? Personally I'm insecure about my posture for example, so I try and work out to target my posture, and consciously remember to correct it often.