I was watching a performance from the great New York based drummer Steve Williams the other day, and couldn't help but notice how much he used on the beat quarter notes in his comping on fast tunes. These downbeats (especially 2, 3, and 4) can be very effective in moving the music along, and are easier to place than upbeats. A good way to work on them is to play a fast tempo, and be able to play any of these quarter notes with the bass drum or snare drum with the hi-hat on 2 and 4 and the right hand playing the standard ride rhythm. Then try it with straight quarter notes on the ride, and also the backwards ride rhythm (8th notes on 1 and 3 and quarters on 2 and 4). Finally, do this with the hi-hat comping on the downbeats as well.
I filmed myself playing a bit, using this concept. I'm loosely playing Charlie Parker's "Constellation" and then play a few choruses of comping before playing the outhead again. It took forever to edit, so I'm hoping my learning curve is as swift as the tempo! :)