So do you know how far you hit the ball?
I am not talking about your driver. Although it is handy to know how far you can carry the driver so you can determine whether you can comfortably carry that lurking fairway bunker or not.
You really need to know how far you hit the ball with each club on average. Most people think they know but they totally overestimate how far they hit the ball. The result is less greens in regulation. Either because they are coming up short of the green or they are trying to hit it too hard.
I use a Flightscope Launch Monitor at Morack to measure the distances of each club in what I call a Gapping Session. I then make up a little card with the distances written on them so you take the guesswork out of choosing the right club. Many people to go to the trouble of using a GPS device to measure the distance they have to the flag but they are letting themselves down by not knowing how far they hit the ball.
If you only hit 3 more greens in regulation in your next round (by hitting the right club) that is going to at least save you 3 strokes a round (probably more) for little effort.