When I'm doing well, I absolutely do keep a food diary. I even had a rubber stamp made so I could have neat little columns of everything:
time, food, WW points, total cal, fat grams, saturated fat grams, grams of carbs, grams of fiber, and grams of protein.
Then I'd add it up at the end of the day and figure out what % of calories came from fat/carbs/protein and try to get my ratios close to 20/40/40 (or 20/30/50). I also had a target of 25g of fiber per day in addition to whatever my WW point limit was at the time. (I'd keep a running balance of available WW flexpoints in the upper right corner.)
Really, it makes a huge difference, even when I'm purely recording stuff instead of trying to hit various targets. I found www.nutritiondata.com to be very helpful.
I know not everyone is as anal about that stuff as I am, but when i record something, I record it. You should see my exercise and TTC records, too. :) Whatever you can track would probably be helpful.