A range of things you could do
1 You may want to start your descent earlier so you don't have to pull as much power off.
2 try leaning to peak after you pull power back to keep things warm.
3 make sure your CHT are reasonably low (less than 350) before you start down
4 remember going down is where you get to make up the time you lost going up (if its smooth come down in the yellow arc with some power on)
Finally, as long as you are running cool there doesn't seem to be any conclusive evidence that shock cooling exists (or doesn't).