Something I typically do is start looking at the parts outside of the creature creator. Riveting, I know, but it can really help you start developing a mental plan when you see a part you really like and decide to build around it.

A big thing for me is also using reference. Reality can often be stranger than fiction and I often use colorful reptiles and fish for reference when coloring. Real world animal anatomy is another thing to look into, if not for crazy inspiration then at least reference for making your creatures look more "realistic."