I use a spreadsheet. In the past I put too many variables in and found myself not entering data. I still have a lot of variables but they're easier to enter. Each row of my spreadsheet is a fish I caught, or someone with me caught, rather than a day's fishing. I found this way its easier to see how you caught each fish. Some people may find this excessive but I will continue with these variable until I find there's no pattern (it doesn't help that I majored in statistics!!) date, time, target, species caught, waterway/location, method (bait/lure/fly), pattern, retrieve, moon, tide, cloud cover, swell (if applicable), rain, water temp. then a list of weather variables that I copy and paste from the BOMs observation centres. If this doesn't make sense I'll show you a screen shot. For moon I have days since last full moon (this is the way i found of entering it as a numerical data) and with tide its hours since high tide. Overboard, maybe, but I was once a statistics student!