Having good Body Language is a must for any guy who is serious about getting girls. Learn to have body language like James Bond and you'll be telegraphing your sexual prowess to the world.
Take Up Space
The key to good body language is taking up as much space as possible. Stretch out, be comfortable. Remember this one rule and you'll be well on your way.
Keep the Head Up
Don't look down at the ground. Look up and around. Survey your surroundings. Expose your neck. When you stick out your neck and expose it, it signals others, evolutionarily, that you are not afraid of potential enemies. You don't have to worry because you're an alpha male.
Eye Contact
Eye contact is huge. It might be hard if you're not used to it, but practice holding someone's eyes when you talk. When they talk it's less important. But a man who looks at people when he talks is usually the more dominant one.
Shoulders
Always keep your shoulders back. Do not slouch. Watch any major film actor and they stand with their shoulders back. Exaggerate it if you have to. Nothing screams I'm a loser and I'm not getting any like slouched shoulders.
Chest Out
Make sure your chest is forced out. This should happen naturally if you pull your shoulders back but it's worth mentioning. Think of it like your a peacock. They spread their feathers, you spread your chest out and strut. Guys do this subconsciously when they see women because it is an attractive trait. Learn to control your chest all the time and you'll be attracting constantly.
Uncross your Arms
Don't cross your arms. It signals others that you're closed off or scared and you need to hug yourself. Let your arms hang open and to the side. Don't stick your hands in your pockets either. You don't look alpha and it usually brings your shoulders forward. Remember, taking up space is the key.