Summarize:

Sit and stand with your back straight. Keep your shoulders back.  Good posture conveys poise and confidence. Even when you don't feel confident, projecting confidence to the world makes you more attractive. Some studies show that good posture can act as a positive feedback loop when it comes to confidence. Maintaining good posture can actually boost your mood and build confidence on its own. Keep this in mind if you have a lot of anxiety and feel intimidated by a potential partner. Even the most confident people can hide insecurity. Reminding yourself that it's ok to feel nervous will help you to keep it from showing through. If your confidence is low, it may be difficult to make proper eye contact with others. Holding your gaze for the appropriate amount of time will make you appear more confident, likeable, and attractive to the other person.  When you're speaking with someone one-on-one, make eye contact for 7-10 seconds before looking elsewhere. If you're in a group, this should be 3-5 seconds.  When breaking contact, look to the side or up slightly to appear confident and self-assured. Looking down at your shoes makes you seem anxious or submissive.  Don’t make eye contact for too long. When you "stare," you can come off as intimidating or creepy. The more comfortable you are with yourself, the easier building confidence will be. Even if great self-esteem doesn’t come naturally to you, there are many ways of cultivating it on your own.  Exercise mindfulness and positive self-talk. This can be as simple as telling yourself a few affirmations every morning in the mirror. Avoid admonishing yourself when you make a mistake and instead simply resolve to do better next time.  Write down a list of things you like about yourself. Read it every time you need to cheer up. Set realistic goals. Pick things that you know you can do with some effort. (For example, "learn how to mountain climb" rather than "climb Mount Everest.") Celebrate each step on your way to fulfill that goal.
Maintain good posture. Remember that other men may be just as nervous as you are. Make and hold eye contact longer. Love and accept yourself for who you are.