I use 70 kts and 500 ft decent for just about all aircraft and that works guite fine... gives me the 5 kt "safety" margine to the 65 (student decides to pull too much, etc.) and keeps me (or student) from being too fast.... and adjusting with throttle or applying/releasing pressure on control wheel/stick as needed.
Some instructors tell the students certain RPM for downwind, then another number for base, and a third for final.
That doesn't always work if you're too high or too low!! Give me 70 kts and 500 ft !
Westy