I've found being a writer often requires finding some sort of intellectual stimulation that won't taint your creative palette. Reading fiction, watching television, movies, comic books, and similar can influence my ability to craft original works. I spend a great deal of time depriving myself of media unless it is for research or objective analysis. Here's my rotation to keep my mind fresh without polluting it with external media.
I do a lot of Shovelglove, which is working out with a sledgehammer. I also have a couple of 25 lb. free weights that I use to fill the gaps the Shovelglove misses. I walk a lot, and I ride my single speed bike whenever I get the chance. Yard work, laundry, and light house work doesn't really count. I put that stuff under drudgery rather than stimulation.
I have a guinea pig (Lucy) who is very good at demanding my attention.
I have 17 gigabytes of audio, including white, pink, and brown noise. I strongly recommend Immediate's "Trailerhead" album, E.S. Posthumus's "Unearthed" album, and most everything done by Corner Stone Cues or Kerry Muzzey for writing music. Basically these guys make that epic sounding stuff you hear playing during the previews at the movies. For people who like background noise that's just a notch under actual music I'd recommend Darkroom's "Fallout 3" album. If you like metal music, sans lyrics, I'd recommend the Black Mages, Powerglove, or Jeff Loomis.
I'm not an artist, but I love painting on my iPad. I strongly recommend procuring a cheap Wacom Tablet, Sketchbook Pro, and an hour a day just doodling. I like the digital medium because it doesn't require the regular purchase of materials or an additional workspace beyond the computer I already regularly use.
I rarely turn down the opportunity to be near or interact with people, even if I'm just an observer. Table Top RPGs, meeting friends for Coffee, talks over pizza with your grandmother, or a phone call to someone I haven't talked to for awhile are great ways to engage people. This type of stimulation is really important if whatever I'm writing is heavy on dialogue.
This is so important. I don't read nearly as often as I should.
When I'm seeking inspiration the worst place to get it is from the works of other modern writers. The shelves are full of commercially successful, but hopelessly derivative works. Try to find something in the young adult section written about something OTHER THAN angst filled teenage vampires, or prepubescent prognosticators of the mystical arts. (Barf) I personally want to write stuff that makes only the vaguest and accidental references to external works. My library of fictional works is very small as a consequence. Minus Shakespeare's works, I have probably less than ten works of fiction.
I love reading John Milton's "Paradise Lost", Tennyson's "Idylls of the King", and a book on Swedish Fairy Tails. These works are difficult to approach by modern readers and require I do a good deal of research. Finding just the right version of older works is important too. My copy of "Idylls of the King" was published in 1896, with every other version I've found being watered down or edited for a modern reader. I have more than a few books that are in that age range procured at independent booksellers and junk shops because modern equivalents have been dumbed down for a less-than classically educated audience.
I also read a great deal on philosophy. The US Army-Marines Counterinsurgency Manual, Plato, Marcus Aurelius, Epictetus, Leopardi, Emerson, Gracian, Montaigne, James Allen, Ayn Rand, and Sun Tzu are regulars on my reading rotation. I think that anything that didn't relate specifically to the modern world, the subject matter of your writings, or the work-a-day world would work. Like any book of this sort, don't just grab the one off the shelf with the prettiest cover. Having the right version and or translation is very important when the original work was penned in something other than english.
I have three element encyclopedias, one each on Secret Societies, the Psychic World, and Spells that I read whenever everything else holds no interest. I have a book called the Complete Dictionary of Symbols which is fascinating to read. I also have a few books on ancient civilizations, art, religion, and mythology. These relate heavily to my writings and often work both as recreational reading and research materials. Multifaceted works of this nature are always better if they possess a good index and lots of pictures. My copy of "Civilisation" (yes, the British spelling) by Kenneth Clark is wonderfully written, but would be impossible to read without the pictures to help me visualize what he's talking about.
...needlessly searching the internet for random stuff.
...a messed up sleep cycle.
...drama both personally and interpersonally.
...food that freaks you out.
...a hopelessly cluttered workspace.