There are women who like petite feminine skinny men(justin bieber, adam levine, etc) that sort of style, but you can never go wrong with being the alpha male. I walk shoulders back and relaxed, perfect posture head up. I realize smiling shows weakness and talking a lot shows insecurity so I limit both. However recently I've been getting feedback from people that I seem intimidating which scares girls away? Geez, can't a guy be alpha without scary?

humans are social creatures. "dominance" doesn't make you socially dominant, cooperation does. guiding interactions by starting and continuing conversations, inviting people into your life with an attitude that expresses you want them to but it's their choice. when it comes to the social aspect it's about having a cooperative attitude.

the only part between a man and a women were i would see it as strictly a dominant to submissive dynamic is when it comes to sex and intimate or flirtatious touching. were the man tends to be more the one to caresses and the women is the caressed. the man guides her movements. the women gives of more submissive "limp" body language.

SMILE dude. i mean it is a must for 99% of opening. the first eye contact honestly should be a rather submissive smile. you give that more "we're in on something together" look once you feel she's responding positively towards you.

SMILE

with regards to your bieber reference, my friends call me bieber (a taller blonde version) hell ive even had girls come up to me saying lets get a photo with bieber and yet i consider myself alpha.

being alpha doesnt mean you are the most dominant man, it doesnt mean you can beat up every guy in the room, maybe long ago when we hunted and tribes kings were based on strength but in the 21st century this isnt relevant anymore, sure having a physical presence is a good thing but its not everything.

leading your interactions, being the decision maker, the one people turn to when they have a problem or cant make their own decision, thats being Alpha. you are the leader of the group or interaction through respect or social skills not fear.

and smiling doesnt show weakness it shows confidence, you are sure of your self and therefor your body language should be open and confident.