You definitely need to know your clubs, and knowing when, if, and how to use them effectively for each shot type they are available for. Having a good idea of how far each clubs hits the ball in the air before it lands and rolls, doesn't roll. With the shorter clubs and wedges the ball may back up after landing.
You have to know when to hold 'em and when to fold 'em
In other words you have to know when it is and isn't appropriate to attempt a shot that has a low % chance of being successful.
Drive for show. Putt for dough
Hitting greens in regulation (GIR) is more important than hitting fairways - as long as you don't hit tee shots into the deep rough. On many courses the first cut of rough does not hinder your GIR all that much. The exception is USGA, US Open courses - because they are set up with deeper than normal rough that extracts a penalty if you miss one of their also narrower than for regular tournament play fairways.
Use whatever aids are legal
A calculator.
Mental or written tee, fairway, rough, and green notes.
Shot Pal & Putter Pal (WGT or VGG Caddy)
Using the Chip/Pitch shot mode green grid as an approach shot wind compensation aiming aid, and putt break reading and aiming aid once you are on the green.
Using Windows Task Manger's CPU Performance display for timing your swing down stroke to help make the swing meter smoother.
Use Task Manager to advantage
Using the Pitch/Chip shot mode - putting green grid.