I like to rapidly swap between the brush tool and eraser tool. I like to "sculpt" objects and characters by constantly erasing and redrawing pieces, then duplicating and iterating until I find a sketch worth inking and shading.
Basically I always sketch before inking. It makes the whole process much easier. It is appropriate to rush each sketch, being very sloppy, as the entire purpose is to see a preview of what could be finalized. For this style, shapes are more important than lines.
In the coming weeks I would like to explore new mediums, such as water colors and oil paints. Every now and then I emphasize a particular branch that game development offers, from art, programming, design, to audio. Trying new things is the only way to grow.