I think you did a good job in keeping one axis lines in each parallel! (vertical axis in most, horizontal in 05) In 02 it looks to me that the smaller box has the right angles but side is too short - there's quite a bit of the side of the head showing too -- so the larger box would have the right proportions and the smaller the right angle?

Whenever shapes look boring the two main culprits are: straightening angles and creating symmetry. Try pushing sharper angles on different parts of the body to see if it helps (I like measuring with my pencil to see if my angles match the photo.) Also their bodies are looking pretty symmetrical. The two lying around just look like tubes. Circles and ovals are fine to start with, but there's so much more going on. Adding thoses differences will make your drawing look more interesting as well. Hopefully this made sense and was helpful. More than anything just keeping practicing and experimenting.

Cool style