As for me, it seems like sometimes I can only write a certain scene when I've got the appropriate BGM playing, so I've got YouTube
loaded in one tab while I write about, say, a kick-ass motorcycle chase scene in Word. (Recently, I've been finding some good songs by typing in "ost" followed by a word that describes the scene's mood. Like "ost tension" or "ost insanity." Just a little pro tip.
Beyond that, one of the things that helps me - as a character-oriented writer - is to imagine my characters as sprites from a fighting game. Movement, body language, stances, and things like that are all pretty important to me, so it's not uncommon for me to stand in front of my mirror and try to recreate their movements. (Thank the stars for closed doors.) I also put a fairly heavy emphasis on rendering my characters in the story, describing bits and pieces of their appearance, color schemes, tics, and the like. It feels like once I nail how they look and move, their dialogue tends to come a bit more naturally.
Of course, maybe it's because of some deep-rooted wish to make my own fighting game. Or maybe because my brother plays Street Fighter
till dawn while I'm trying to sleep. Brainwashing, or something like that.