A short but useful warm up exercise. 8 notes per hand, then 4 per hand, 3 per hand and finally just two notes, meaning that the next time you begin the sequence the sticking is reversed.
Remember to stay relaxed and try to make all strokes as even as you can. Use a mirror if possible, so you can watch your hands and sticks more easily. Repeat, using a metronome, for at least one minute, at a little under your maximum tempo.
To develop this further, try adding flams to the first note each time you change sticks.