Lol, masturbation is not an inspiration (at least not to me). I think we may simply do it to release stress and to keep working, or simply out of boredom.
Well, never having cleared a room in that manner, I couldn't say, @The Mad Regent . But it might be fun. Bucket list? (I better hurry up.)
Traveling. Far and away, this is the one thing I do that I think helps my writing the most. I'm lucky in that I travel a lot for work, so probably not everyone has as much opportunity, but it's great if you can. In addition to just exposing you to new things you can incorporate into a story, it's such a total sensory experience that it really makes you think about how you'd describe things in detail--smells, sounds, visuals, etc.
Well music seems to be topping the poll. I'll concur on that score and fess many a score prods my creativity. I've discovered too, more by luck than design that: walking, chewing gum, taking a bath, cycling, coffee drinking, people watching, a pint (alone) in the local pub and taking in a good view all serve to spark ideas. Now; if I could manage all those at the same time that'd be some Magnum opus I'd be able to bang out!