It is pretty crazy. Some characters (Gaston, Dr Facilier, Jafar) have less people, so it is easier to get a picture. However, Maleficent and the Evil Queen have a massive amount of people around them. I guess it might be a little easier if you go to the courtyard a few minutes before they arrive, as some people don't know there's a meet n greet. As soon as they get there, though, people see them and go bananas.