Here's an exercise/warm-up that I've been messing around with lately. Basically it's just a bar of alternating accented single drags followed by a bar of accented single paradiddles. This one was inspired by the beautiful snare drumming of Philly Joe Jones and Kenny "Mean Streets" Washington.
I've been practicing this one at a faster tempo these days with the idea of matching the phrasing of the doubles of the paradiddles with the doubles of the drags in the bar preceding them. You have to play this at a brisker pace for this to make sense.
Don't forget to really crank those accents.
(and play it with brushes too!)
So here you go: