Through college, I had a weak posture, submissive body language, and tended to fidget/move around. I often looked goofy.
About six months ago, I decided to improve all that. I consciously developed an upright, chest-out posture. I cut down or eliminated unnecessary motions. I keep my hands extended and parallel to the arms, instead of close-fisted and angled inwards. I keep my chin up and my gaze high. I keep my legs outward and, when comfortable, spread apart.
By now, it's all become second nature. And it works. Women react much more strongly to me (in a good way). I feel more confident. My body image has greatly improved.
As software developers, most of us spend a lot of time seated in chairs and have less than Adonis-like physiques. I highly recommend body language hacking.