While you might think it's common knowledge for every man, that at birth they inherently have the skills to squeeze out those man fibers with ease but you would be surprised the number of womanly men who can't. Al Bundy would turn over in his future grave to see that you even typed this into Google but anyway here it is,
How To Grow A Beard
1. Flex At Every Opportunity
This too should go without saying but any chance you can interrupt your girlfriend or a random's conversation by flexing through the pain of listening to them, take it. It's imperative that squeeze every muscle on your body at once, the closer you get to injury the more hair will spring from your face.
2. Pick Fights With Strangers
Any true American knows that it's Un-American not to fight a random stranger who doesn't look and act like you in every way. Whether it's the glasses they wear or the cut of their jib unload on them with a furious anger until more hair appears on your face.
My personal favorite, cover your face in dirt. Mud is an acceptable substitute but only when you are in a full Arnold costume from Predator. Specifically dirt from a baseball diamond, which is know to have massive and explosive beard growing effects!
In all seriousness, use something that keeps your skin clean and healthy. Genetics play a big role in it but you can always aid in the process by using beard enhancing products. If all else fails and you don't have the money to invest in proper hair and beard care products follow the steps above and surely someone will feel sorry enough for you and buy them.