Good airmanship in piston engine aircrafts in my books includes planning the decent in such a manner that power is NEVER reduced to idle at any time during the decent.
In a fixed pitch single, I never reduce RPM below 1800. Saves shock cooling, ensures the engine is kept up to temperature (and producing heat for carburretor), prevents plug fouling, does not frighten any unfortunate passengers to mention but a few benefits. In most cases, it simply means starting the decent a bit earlier.
Enjoy the flying.
PS