You can't just slink submissively into the room. On the other hand, you can't assault everyone's senses and announce that you have arrived.

Neither of those will do.

When you enter a room, you need to walk in confidently, with either a smile (if you're looking at someone), or just a hint of one - just to let everyone know that you're happy and comfortable.

Walk in. Don't run.

Don't explode into the room. Walk in.

Ease your way casually into the room - your speed should be somewhat slow and relaxed.

Keep your head up, back straight and keep your shoulders back.

You want to be standing at your full height (most girls prefer men who are taller than they are). Whatever you do, don't stick your nose up in the air, don't pose, and don't look rigid or mechanical. Practice this in front of a mirror if you have to. You want to be fluid and confident.

Standing up straight is a major sign of confidence, and women definitely respond to, and take notice of this.

Walk into the room like you have a purpose - like you know why you're here and what you're doing.

Stop or hesitate for a brief second at the door and scan the crowd for people that you know. If you see someone you know, walk towards them purposefully, giving them a big smile and start talking to them.

If you don't see anyone you know, single someone out and walk over to them with a big smile and introduce yourself to them - act friendly, as if you've known them all your life and begin a conversation with them. Then work the room.