I am focusing purely on loose sketches for this one. I enjoy doing line work the most - I've been doing it since I was born :)
Veteran animation master Glen Keane, during a talk about his art and passion in general, said that the work he enjoyed looking at the most, and that he found most inspiring, were the line scribbles of small children. There is a playfulness and character to children's line drawings, and it gets lost once our hands and minds get conditioned. I like keeping my line playful whenever I can - it's a nice counterpoint to the strictures and rigidity of everyday "adult" work.