James,
I've had the same problem in the past. I think part of it is I have somewhat of a "resting-bitch-face" for dudes. If I'm thinking about something (and often times, I am connecting the dots on something or other) then I look slightly upset / angry even when I'm not at all. Combine that with social interactions, and everyone seems to think you're mad at them.
Another problem I've had is being selectively social / anti-social.
When I'm not feeling super social, I find myself coming off as "too cool" by not providing much energy to conversation. People think I don't give a fuck about what they're saying, or them.
Then, when I am feeling social and high energy (what people decide is the "real me") and I'm providing lots of energy to conversation, people notice that perhaps I wasn't like that with them our last conversation.
Active listening can take care of this, especially if you can turn on your genuine interest in everybody.
People have a tendency to be egocentric, and think that it is
them that caused
you to act a certain way. They believe that because of something they did, or how you interpreted something they did, that you are now treating them differently. "He's just always a dick to me for some reason" or "he just doesn't seem to like me that much".
Eventually, people like to stop blaming themselves (because they really haven't done anything), take on somewhat of a victim mentality, and blame YOU for their feelings in the situation. "He's just a douchebag and thinks he's better than everyone else".
So now you've taken a person that could have been your friend, and
because of you not giving them enough attention, they believe that you don't like them for x,y,z reasons, and get mad at you for it.
Lastly, in my case, I tease people lightheartedly a lot. I've only just recently gotten better at making it very clear that I'm kidding.
"I'm Just Kidding" + Touch usually does the trick.
If this is how you're coming off to strangers, I would just try to show more of a genuine interest in other people, if their reactions to your.. presence.. bothers you. Tweaking your body language to have more of a welcoming personality and vibe - an openness to engage - is also largely beneficial.
Sources:
Working with all women and gay guys for over a year, and interacting with hundreds of other "sensitive" individuals throughout life
Hue