The single best portrait tip ...
I don't remember where exactly, but I do remember reading somewhere to take a big bag of sweets with me to Cambodia. It said it would be good to give the children something after you have photographed them.
With this girl, I thought, "Why not give her the sweets before I take the shot?" I waited for her to open it and pop one before opening the shutter ... and you can see the effect it had on her.
Siem Reap, Cambodia