I've been dissatisfied with my working practices (and the end results) for a while now and have started putting some changes into effect that will hopefully make creating artwork easier and more enjoyable for me.
Part of this is a renewed focus on proper experimentation in my sketchbook. I've started dicking about with cheap felt pens, building up characters in blocks of colours, with limited line work. It's pretty rough at the moment, but I'm feeling reinvigorated by the process, so it's definitely doing some good.