I use exposure journal. Usually data which I write down varies. It might be just quick note describing subject or there might be lot of information about visualization, zones, SBR, lens, filters, my own mood, notes about subject, etc

However there's always the film cassette number and side (I use red and green dots for different sides of each numbered film cassette), camera, film, EI and lens.

So the journal also works as base of my negative archive. Also as an backup.

It's also useful when tracking down some problem like light leak. I can easily check the used film cassette etc.

On a longer trips it's sometimes like a full journal.

The one thing that I don't record on the journal is the development and printing data. Those are kept in different notes along the negatives.

Also, I don't like restrictive forms, so I write everything on plain notebook. Some 15 or 20 years ago I tried to use printed forms (like one introduced in Adams books) but it just didn't work for me.

Keeping notes is habit that I can't work without. I use separate note even for 35mm snapshots...

For a last; the journal also works as quick reference. In have resiprocity curves, filter corrections, etc. Information on it.