Well, I'm a simple person (and I know I'll get flamed for this, but ... ) so when I was in the OP's position I followed everything my instructor said.
EXCEPT that I trimmed the aeroplane just a tiny tad nose down, so that if my attention should stray from my airspeed to one of those other things that are so important (revs, radio, lookout, wind, carb ice ..... ) then I knew that my airspeed would always be a touch higher than I needed, rather than a touch lower.
This allowed me just a little more spare brain power for all those other things that are in PPL training manuals.
SD