When I am busy at my desk, and work permits, I enjoy listening to something other than the normal sounds of a day (lawnmower, fan, etc.). Regularly, it is music, audio books, or documentaries. The subject matter isn't specific, but whatever is interesting and readily available. I do this during tasks that don't require heavy concentration, such as flatting in colors, so that I can liven the mood. If I listen to quick-paced music, then it can hype me up and I work faster, or if I'm working in slow and delicate movements, then relaxing music suits. Anything not music just needs to be interesting.
It is nice to gain new knowledge, regardless if it is applicable to one's self, but I use everything that I know to make my work better. For example: from listening to lectures about the study of light, I came up with new ideas that I can experiment with in my usage of light and color, such as different surfaces' characteristics of handling light. Fortunately, visual elements are not all that can benefit! If I wanted to design an underground environment, I can pull from my, previously trivial, knowledge of ant colonies and how they form their underground tunnel system. It is always a wonderful surprise when the discovery is made of dormant knowledge being put to practical use. Sooner or later, I can use it all.
I always keep my mind open to take in new content so I may enrich my library and become a better artist. I do not know how some learnings will be beneficial, but I am certain they will, and it may even happen without me being aware. This has been something helpful to me and perhaps it can for you too.
Regardless, we have minds and should fill them up!