I don't exactly have a 2 + 2 formula to get a great sun flare shot. It takes a lot of practice to get the desired look you are going for. I still don't think I have mastered it. But I can share a few pointers that helped me get these shots.
I always take them late in the day, right before the sun goes down. The sun is less intense that way.
I meter and focus on the subject. Which can be difficult is you are using autofocus. I have to manual focus.
I hope I am not disappointing anyone. It really is that simple. Be sure to practice, practice, practice and practice some more. It took me a while to get it but once I did, it quickly become one of my favorite shots!
*Update- As pointed out in the comments. With the first shot there was a tree to block most of the sunlight. I kept moving around until I found the exact position that let in just enough light. Which gave me a great shot. In the second picture, it was a little more difficult but I used their faces to block most of the light. I did the same thing with the third picture. You need to use something to block the sunlight. Most of the time I use people but you can use buildings, trees, etc.