Every now and then, I'd suggest taking a day or afternoon off from whatever routine you have, and do something creative without any pressure to achieve an outcome. No checklist of items to cross off in this time, but rather just let go, relax and have fun.
In my case, I got into the city three hours before last Friday's Radioactive Lounge podcast, and spent it wandering the city with my camera. With nowhere to be for hours, I just wandered around taking photos and letting life pass me by. Here are some results of the day.
Days like these are the main reasons I prefer working part-time. A creative person needs time to do nothing but absorb, to refill the tank, to decompress and re-charge the eyes and mind... I have to remember to do this more often.