Keep things simple to start. Simplicity is key to further exploration. A simple cut paper circle will evolve suns and planets. Larger ovals will produce the bases for animal faces. A dog's face can be oval-shaped to the side or up and down.
Ears are also oval shaped, but come in all kinds of shapes and sizes.
You could, if you wanted, make a puppet totally out of cut oval shapes. In fact, it's kind of fun to limit yourself to start. Those of you who work with young children are all familiar with Eric Carl's, The Very Hungry Caterpillar. The wonderful thing about that character is its simplicity. Its face is oval.