As much as we would all like to make more true friends, usually there's a lot of trial and error in the process. I'd have to say, in all my years of meeting people and getting to know them, there's maybe only 4 people I know who I can call my true friends.
In reality though, I don't think it's wise to go searching for true friends, because more-than-likely, you will meet your true friends through simple, everyday situations, when you aren't thinking about finding a friend.