I'll probably get flamed for this but anyway....
When learned many years ago in the 150 I was taught to wind in 4 turns of trim when reducing power on base leg. Much trim re-correction followed and I continued to fly like that until one day on a check ride in the US an instructor said "Why are you doing all that? You don't need to touch the the trim! Look".
He proceeded to show that for each power adjustment and flap setting the aircraft would settle out at close the correct speed anyway. It's designed that way. All the trim adjustments just caused hunting.
Maybe students aren't taught that way now, maybe it was done to make sure they slowed down before putting in flaps, and maybe I unconciously operate trim anyway, but I'm not aware of making many adjustments or having control forces during the approach nowadays and the PA-28-161 settles nicely at the POH 63Kts full flap from what is close to the cruise trim setting. Of course other aircraft may well have different characteristics.
David