A few ideas come to mind:
Do as described above--triage your reading pile as if it was your In-Box.
OR, you could sort into some other sort of contexts that make sense for you--"easy" reading for times when that is all you can handle, "quick" reading for times when you have "weird" pocket of free time show up (when you are on hold w/someone on the phone), "bedtime" reading...whatever. I am making up the contexts, modify as you see fit for your life.
But, this is could get to be too much work, where you spend too much time getting ready to read, and not enough time reading. If that is the case, you could be totally non-methodical about it and...gasp... just START reading whatever is on top!
