The most recognized quality of an Alpha Male/Female is confidence. It doesn't matter how awesome you are in every other aspect of life, if you're not confident then you're not Alpha. That's it. Want proof? Go to a dance club and look at every douche in there. Most of the people who you'll see will be supremely confident in themselves, but may not necessarily be an Alpha.
Now, these tips won't make you an Alpha. I can guarantee that just by doing them that you will be feel, and most importantly, be more confident.
Not screaming, just louder. When you're walking down the street and someone randomly says "hi" how do you respond? With a quick and quite "hey..." that they can barely hear/understand or with a "Hey. How are you?" that could easily be heard and understood a few feet away.
It's the same concept when you're having regular conversation with someone. When you make it so the other person has to lean in, strain to hear you, and ask you to repeat yourself over and over it makes it look like you aren't confident in what you're saying.
When you look like you're not confident in what you're saying, you look less confident overall. When this happens people will automatically discount your opinions.
If you're wrong then so be it. But don't let your opinion get brushed to the side because you're afraid to speak up.
Put Your Shoulder Blades in Your Back Pockets
Time to get physical. Stand up, pinch your shoulder blades together, and then push them down like you're trying to put them in your back pockets.
What just happened?
You're standing up straighter than you usual do and your chest isn't caved in anymore. This is the look of someone who is confident and strong.
Hell...it'll even make you look a few inches taller. Guys, don't lie, you know you're always looking to gain an inch or two.
The best part about this one isn't that you look more confident, but that you actually FEEL more confident. Physical actions can trigger emotional responses just like emotional responses will trigger physical actions.
Go look in a mirror and alternate between smiling and frowning. If you pay attention to your feelings, you can actually feel yourself become a bit happier when you smile and sadder when you frown.
Chin Parallel to the Ground
Why do Soldiers and Marines look supremely confident when they're in their dress uniforms?
Because most people are conditioned to see those uniforms and think "whoa...that dude's bad ass". Wearing a military dress uniform isn't something everyone can do.
Raising your chin and keeping it parallel to the ground is something that you CAN do though. This goes hand in hand with the point before this, and creates a physical presence that says "I'm confident, I know it, I got this."
Or for some it screams "I'm sexy and I know it." Really it all just depends on your style...
Move and Talk Slower
Moving and talking slower are things that are so simple and unassuming that most don't even think that they would help them out.
When you get into a conversation and start rattling off sentence after sentence at a pace so fast that people have to work to listen to you. Add in that most people are lazy and they won't do the work to listen to you babble.
Speaking slower projects a calm confidence that people will cause people to somewhat enjoy listening to you. Just think of Morgan Freeman narrating anything...
Moving slower has the same effect. Unless you're playing a sport, moving fast gives the impression that you're either a) in a rush to get somewhere or b) that you're nervous.
Both of these will essentially tell whoever you're talking to that you'd rather be someplace else. No bueno...