As this was my first attempt at animation I had to do some background reading to learn the techniques. Animation is an artform in itself, but fundamentally the skill is based upon close observation of movement and form. So you can bring to bear any drawing skills you have.
Animation is extremely painstaking, because any error to the movement is the only thing the audience will see. When it is right, nobody knows because the illusion is complete.
The combination of Motion Capture driven skeletons and keyframed IK animation worked well- keeping the heavily labour intensive process manageable. Great care was taken in the selection of motion capture data to choose movements that could be integrated into the story and adjusted to match the required expression. Technically the approach was very basic, and hence a bit more labour intensive than strictly necessary, however it was effective.