I have been keeping all my stats for a lot of years. I have a way to write down the stats right on the card, then later put them into my excel spreadsheet. If anyone wants the spreadsheet template, I'd be happy to send it to you.
Fairways I mark in the upper left of the box with just a 1 if I hit, or nothing if I miss.
If I hit the GIR, the number of putts go in the upper right corner. If I missed the green, the number of putts go just to the right of the number I shot on the hole.
Penalty strokes go in the box underneath.
For a sand save attempt, I just mark an S on the bottom line of the box under the score for the hole.
I also keep track of "Easy up and downs" around the green with a simple plus or minus also in the box underneath. Sadly, my EU&D is always well less than 50%. I'm talking U&D's that I'd expect a tour pro to get up and down 90-95% of the time. Looking at the stats, I can see my chipping is horrible.
Because there is so many numbers and dashes and shit, I circle all my pars, and box my birdies. That way, if I see a circle, I can just skip it. When I don't see a circle, I look at the par for the hole and find out how many over I was.
With this simple system I can keep track, on the spreadsheet, Rounds, Fairways, GIR, Putts, Putts per GIR, Sand Saves, Penalty strokes, Pars(or better)/round, Birdies(or better)/round, Penalty Strokes/Round, Scrambling %, and Easy Up and Downs %.
Keeping track like this really shows you where your flaws are, and when I had time to work on things, I would. This year, with practically no playing or practice time, I know I'm a shitty driver, which translates into less GIR's when you are hitting 3 from the tee all the time, and I can't get up and down to save my life. But my Putts/GIR are well under 2. If I could only hit more greens.
If you hit more fairways, you'll hit more greens. But when you miss a lot of greens, you need to get up and down. As I can see from my stats I keep, I'm just a piece of shit this year. I can't hit fairways, and I'm taking a ton of penalty strokes, almost 2 per round. Add to that, when I miss my greens WITHOUT a penalty stroke involved, I am getting up and down, on EASY shots, well less than 50% of the time. That means I'm just not chipping it close enough to make the putt more than 50% of the time.
So what do you work on? Driver, so you're not hitting 3 from the tee or the rough all the time? Or chipping, so that I can get up and down to save bogey or double more often?
My sand save % is well below 5%, and I know if I'm in the bunker, I'm just dead. So my strategy each round revolves a lot around NOT hitting it in bunkers. I'll forsake GIR's just to not have an instant bogey, or WORSE, by plunking it in the sand.
Anyway, I know all this because I keep track. Nobody else I play with keeps track of their stats, and they seem to always inflate their play at the 19th hole. "I was in the fairway all day, how'd I shoot so bad?" I just look at my card and see I hit 4 of 14. I have to go back through their round, and it turns out they hit 6 fairways. I wouldn't call that "all day". "If only I could putt, I'd have beaten you." I'd have 4 three putts on my card, plain as day, then we go back and recount his putts, and he won't have a single 3-putt, but take 34 putts anyway. Lots of 2's. No, I'd have beaten you WORSE if I hadn't 3-putted 4 times. "I shot 80 and must have had 40 putts." I just look at my card and can see exactly how many I took. We go back through the round, and he'd have 33 putts, just like me.
By having the raw stats in front of you, you don't artificially inflate your play. By keeping track, you know exactly where your shortcomings are, and can isolate and fix them.
Month by month, and year by year, I can see my growth and setbacks. Every month brings a new start to make better stats than the previous month.
I tried to play 9 holes without a card this year. I almost died.