Beyond body modification tips, I would recommend being more aware of the general expression on your face.
Perhaps being in a new environment you are lacking a bit of social confidence and projecting an "unapproachable" expression.
For me personally, I have to almost conciously remind myself to sort of smile or my default look can give the impression like I'm upset or scowling.
I recommend mirror work taking a look at yourself honestly and ask, "Would I want to come up and talk to me?".
Practice a warm friendly expression by sort of smiling with the eyes as opposed with the mouth. I notice when I do this, that frowing muscles around the forhead relax & release, creating an instant improvement in overall facial attractiveness (compared to a stressed out or sour look) and generally makes me look more relaxed, friendly, confident and more approachable based on experience.
Don't get me wrong, I'm not saying this is a magic bullet and get it right and women will be throwing themselves at you. But, if this is an issue it can be an instant deal breaker. If a woman makes eye contact with you and it appears to her that you are angry or in a bad mood, she will not likely respond positively if at all.
Just some thoughts to bounce off you for what it's worth. This may not be a problem for you at all, but maybe others can relate.
Good luck!
-Giggitty