Rule of third, Framing, Avoid the middle and leading lines

Monster's university has a rule of third in this piece of concept art as mikey and sully are placed either on the two vertical or horizontal lines, This is what we focus on first.

Rapunzel uses Framing in this concept art as the first thing you notice is the castle and it's lights in the background before you notice the boats or the people in the boats at the front.

 

This Piece of concept art from The Croods uses the technique of avoiding the middle and this is effective because it gives the image balance and looks a lot better