Food for thought (juice for creativity) from cartoonist Bob Camp:
(from a post on his blog called The "ON MODEL" rut)
Here's my design approach:
I have an idea of a character and the overall form of the show, comic or whatever. Then I start experimenting, scribbling mostly like in the horse and pig drawings I posted the other day. VERY loose. I try to get to know the character first. Draw them as many times as it takes to start to feel like you are getting some where. NEVER start carving out thick black lines in an attempt to get a style. Lots of people perfect a style but do not perfect the underlying character construction, line of action etc. I catch myself doing this too. All icing and no cake. It's a dead end trap. You spend so much time working on a beautiful rendering over a badly constructed or boring drawing.
Once you start getting to know your character, try to create a shorthand version. I find in storyboarding that after I've drawn a character a few dozen times I have developed a shortcut way to draw them that is always more alive, simple and yes funnier. Now that you know who you are drawing you can start to refine the individual moods and emotional states that you will put him through. You know when Ren gets really angry he suddenly develops harder angles and much more realistic anatomy?
Here's the main point of this whole diatribe:
The style you choose for a drawing should be about who your character is, what he/she is feeling. It's about how to use style as another layer to tell the story in a funnier way and not as a way to design the life out of it!
Do not grip your pencil tightly! Hold it loosely and use gesture. Use your whole arm. Do not draw slowly. make quick confident gestures/strokes. These gestures will bring you character to life and you always want to push the pose and expression because you know that once the drawings are translated into animation, much of the life will be corrected out of it.
Being a good cartoonist is like being a jazz musician. You need have great chops and not be afraid to..
Store all that away the next time you take your pencil for a spin :)