Speaking of OCD, I made myself a brewing journal using Adobe InDesign, but I'm sure Word or something similar would work too, just not as fancy.
I keep three sections:
1) Costs
2) Recipes
3) Journal
Costs - I keep a rounded log of brewing-related costs because I was curious if it would ever be financially feasible. Includes equipment, yeasts, juice, bottles etc. along with a running tally of the number of 12 oz bottles we have made. I'm on my fourth 5-gallon batch and each bottle is costing about $1.36, less than at a bar, but still a little more than store-bought 6-pack. I'll be excited when each one is less than a dollar.
Recipes - The recipe for each batch we do, including ingredients, yeast, OG, SG at various points, FG, final yield (in bottles), process notes, and total time. Granted, we haven't "re-used" a recipe yet, as I'm still in the experimental changing of one factor each batch to decide what juice, yeast, and sugars we prefer.
Journal - The "diary" type section where I jot down what I did on a certain day. I keep the date, but also not that it is, say "Batch #3 Day 15" so I don't have to do the math each time. I find it helpful because when you brew around a busy work schedule sometimes you forget just how many weeks it's been in secondary. Also if something worked well, I can go back and look at it for reference.
So yeah, pretty detailed - sorry - but that's what I do. I, of course, seem to like highly detailed information, despite finding that brewing is not THAT exact of a science :cross: