I keep a brew log book with an index of recipes, some charts and data sheets (for on the fly calculating), any of my comp score sheets and some other misc items.
I also keep the recipe sheets I print out from ProMash, but I have modified them to help me track my brews and thought I'd share it here. It's two simple excel spreadsheets that I print out before printing my recipes/water usage report. I then record certain parameters of the brew day as I go along. I can adjust on the fly and the next time I brew, I can make changes in the recipe or process.
If anybody would like a copy of the files, PM with your email.
Here are the templates:
And here they are with recipes and water usage printed over them (highlighted areas) and some of my notes: