Keep stats on an Excel spreadsheet. From left to right, the columns are: Date, Course Par, My Score, Over/Under par, Course Played, score to par on holes 1-6, 7-12 and 13-18, 3-putts, Total Putts, Greens in Regulation, followed by columns for eagles, birdies, pars, bogies,etc. I've been doing this since 1988 and it's now become as much force of habit as anything else. Last year was my best year ever statistically, and I considered discontinuing my practice this year, but a friend of mine convinced me to keep going. Since I also have a column for the course I played, it also helps me go back and see when I might have played a certain course. I also keep a separate spreadsheet with hole-by-hole scores on my home course. I have to say that I am able to spot trends from time-to-time that show me what I need to work on.