You can make friends if you smile and talk about what you have in common start with a greeting and take it from there. If you have something in common to talk about you can become naturally friendlier.
Easy, just wish for everyone else what you wish for yourself and act by that. So, let's say.. your friend has lost her car key and is missing a very important appointment. On the other hand, you really wanted to go somewhere. You wouldn't like to miss an important appointment, would you? Therefore, your reaction will be immediate: you hand her the keys and wish her good luck. That's true friendship.
I would do that for my true friends that I've known for 10 or more years. But my thing is that meeting new people and talking to them is sometimes hard for me. Unless it is required like at work, if your in sales and you have no choice but to talk.