I used to have a set rotation but gave that up a few years ago. It seemed to regimented to me. I have a good idea of what I haven't used for a while and that usually guides me, but sometimes you're just jonesin' for that one particular razor lol.
That being said, I used to save the heavy grinds for long growth days but nowadays I use whatever. Perfect example: yesterday I mowed down a week old beard with a small Boker extra hollow and got a great shave - you don't see many guys bragging about that around here
