One thing that I do occasionally, is to play something over and over again, well past the point when I am sick of it and bored with it--there is a point out there when it stops being boring and you start to hear it completely differently--of course, you can't do it when there is anyone else within earshot--not only won't it stop being boring to them, they will never, in a million years, want to hear it again--(sometimes being a musician is a very solitary effort)--