I think that perhaps you have to be interesting, the other person, to a degree, must be intrigued by you and find your company to their tastes before they'll be your friend.
Finding someone who truly complements you is difficult, most people settle for someone with whom they moderately get along with.
Certainly, being friendly can't go wrong.
But, you must also show that you are assertive so that the person knows that they cannot treat you badly.
I think that making true friends is one of the hardest things you can do as a person - a lot of it requires perseverance, understanding and willingness to adapt.
Making fake friends is easy.