A creative dump mostly when drawing isn't an option. Writing for me started years ago when I was playing tabletop D&D & V:TM and outlining plots, creating characters etc, which would then inspire me to draw the character (and sometimes scenarios) based on the descriptions. 

While I don't have nearly the time I did, RPing is always a great way to express yourself as creatively as you can, even if it's only to entertain yourself.