My method is pretty straight forward. Every rifle has it's own book. I start with all the details of the build plus a copy of reamer specs. Then, I record the touch length of all the bullets I am considering for that rifle, along with base to datum measurements of first three firings on my brass (these measurements come in handy).
When I'm reloading, I enter all details of the components & loads and what I'm testing..... pressure/velocity, ladder, seating depth, etc.
At the range, I enter date, temperature, pressure, humidity and wind speed & angle. Then as I shoot, I enter velocities, average velocity, SD and ES.
The last entry is rounds fired and an update on total round count for that barrel.
Simple, but gets the job done.