Years ago, when I was a student pilot it was common to hear that you should select full flaps "when the landing is assured". In other words, make sure you can glide to the runway if you lose an engine. Nowadays, the FAA emphasizes the stabilized approach concept and Chpt 8 cited below seems to support the concept. I currently believe in setting final flaps when rolling out on final approach rather than waiting till short final or very close to the threshold.
What do you favor and what do FAA Examiners favor for CFI's to teach?
Reference: Chapter 8 (“Approach and Landing”) in the FAA’s Airplane Flying Handbook?
"After aligning the airplane with the runway centerline, the final flap setting should be completed and the pitch attitude adjusted as required for the desired rate of descent. Slight adjustments in pitch and power may be necessary to maintain the descent attitude and the desired approach airspeed."