It's hard to make friends if you stay alone all the time. It’s easier to make friends when you have similar interests.
Don’r be afraid to show people what you are really good at. Talk about the things you like and do best.
Look at people in the eyes when you talk to them.
Be a good listner. Let people talk about themselves before talking about yourself.
Be friendly to a lot of people. Try to help your friends when they are in trouble because a friend in need is a friend indeed. That way you’ll have a bigger group to choose from and have more chances to make friends.