If you fish often you should keep a simple log that captures the location, date, time, bait used and species caught. If you're the analytical type you can add tide, moon phase, weather, etc... Why keep a log? When the next fishing season starts, the last thing you want to have to do is try to guess your previous year's successes. Guessing normally means you will end up fishing in the wrong place at the wrong time. The log doesn't have to be anything fancy but it should provide enough data to give you a good starting point.