I've kept pretty detailed notes on my fishing trips for the last six years or so. On a several day fishing trip, I'll bring a small notebook to jot down some observations. Once I'm back, I download the pictures from my digital camera, grab the NOAA image of flow rates if it's been a river trip, and check the weather records from the closest observation center. A few times, I've even downloaded satellite images to reinforce locations. I then create a Word document and do a day-by-day summary, as best I can, of the events of the trip, including the more interesting fish photos, the flows, and location / scenery pictures. I record which flies seemed to work best (and which ones did not), what hatches I observed, and conclude with key points to remember on future trips. Over the last six years, I've fished at least 28 rivers and 13 lakes in Washington alone. Some I fish every year, often multiple times; others I have only fished once or twice. My notes are very helpful when I'm preparing for a trip and help guide my flytying. And the pictures help me remember some of the best trips and moments with friends on those trip in the dark, cold, rainy days of February. I'm becoming a little sloppy about keeping detailed records of places that I fish very frequently, but if I've taken some nice pictures or if I'm fishing with a friend, I'm much more likely to produce a short report. Like Jumbo, I will also jot down interesting tidbits that I glean off various fishing boards for places that I might want to fish in the future. I really think that it has been worth the effort.
Steve