Hi Frisky,
I am a very sociable person and have tons of very diverse friends (only a few close ones though, the word friend is used way too easily in the English language.)
Dave made some excellent suggestions about meeting people.
What I found out in life is that a lot of people tend to open up when others are interested in them. An example would be if you see a lady all the time at the grocery store and one day she has a very nice dress, compliment her.
If an acquaintance mentions a sick child or is going to school, ask them about it when you see them again. In order to communicate with people, one needs to be interested in people (I am not speaking about being nosy or gossipy here, just being open).
Being open minded when meeting other people is also very important. Case in point, one poster here made a generalization about a group of people I belong to (AA) without even knowing me. because I am in AA, he assumes I am a weirdo.
If this had been a conversation in real life and I had met him for the first time, I would not be interested in pursuing a friendship with that person.
I have a wide variety of friends and I meet them on our common grounds. For example a good friend of mine is an old fashioned monarchist. I would never engage in a political discussion with him (I am way on the left). When we speak, we talk about our common love of animals and our passion for horseback riding.
So basically: be interested in others, don't make assumptions about them (making assumptions is making an ass of ourselves LOL) follow through in subsequent meetings (it means not being self centered but caring about others) and meet people on the common grounds you have steering clear of the areas where you agree to disagree.
Isn't volunteering awesome? I volunteer at a food bank once a week and I get to meet very interesting people on a regular basis.