Be a Risk Taker
When you lack confidence, it's easier to stay with the familiar. Real confidence-boosting power comes from tackling something new, though. You may not succeed right away, but when you do, the experience is liberating. Many people never achieve their full potential -- not because the opportunities aren't out there, but because they're afraid to risk failure. Think of it this way: If you aren't taking risks, you aren't growing as a person. When you fail at a new challenge, it's a sign you're getting somewhere. It's one more mistake you won't make again.
There's an extra added bonus, too. Developing self-confidence is a process, and once you've worked through the fear of failing, it gets easier. You know you'll survive the humiliation of revealing your imperfect self, and you'll begin to realize that a few initial failures are a small price to pay for learning and experiencing new things.