Movement - DONT be fidgety and jerky. Of course this is easier said than done but notice how confident men are typically successful with women? They can make very controlled movements. Confident men don't get restless leg syndrome around women. They don't fidget with their fingers. Calm down, it makes you seem more comfortable and approachable.
Relax - Lean back and relax for a change. Let your arms hang down at your sides, and make yourself as comfortable as you possibly can. By sitting forward with their arms folded makes you look closed off.
Be Spacious - Take up as much space as possible. This is a "territorial" thing that all people notice subconsciously. If people see you taking up this space they will automatically assume you to be the alpha in the room. Subconsciously, women are attracted to alpha males.
Walking Posture - Walk with great posture. If you walk with your head down with your hands in your pocket you will look completely unapproachable. Walk with your back straight, with your head tilted up just a bit. Stick your chest out and bring your shoulders back. This subconsciously shows women what they are most attracted too, confidence.
Open Yourself - When approaching women have your palms slightly exposed with your arms at your sides. Your legs should be shoulder width apart (or out in front of you if you are sitting). Don't ever cross your arms or your legs as this is a signal for being "closed" off.
Be Calm and Indifferent - You never want to show to much emotion at any given time, this makes you seem as if you aren't in control of your life or your situation.
Tonality - While this is technically "speaking" it's more body language then anything else. People who talk fast are usually left in the dust because they either A) Talk too fast for people to comprehend or B) Are embarrassing to talk too. Talking slower allows you to be more in control of what you say, it also stops you from making embarrassing mistakes such as stuttering which is a MASSIVE sign of being nervous!
The GREAT NEWS is this is only scratching the surface. Check out the link in the Resources section below if you want a step-by-step on How To Make Every Girl Want You.