For films I would tend to note date of developing (usually not more than a week or two after taking - although that has been getting longer as of late), film&speed, developer&time. I would also usually write down the main locations where the film was shot, more as a quick aide-memoire if ever I have cause to just flick through the folder. And I add an index, so that if I ever want to re-print any negative I can look on the back of the print, retrieve the index and then hopefully find the neg without too much swearing and cussin'. A bit like the Talented Ms Andrea Ingram, who rather cleverly files her negs 'down the back of the sofa' so she can find them again when needs be.
4x5 negs might get a bit more treatment - if I've bothered to write down anything when 'in the field' - such as aperture, time of day, general lighting conditions, what I had for tea, that sort of thing.
If I ever like a neg enough to print it - an increasingly uncommon event, it has to be said - then I would note the following: f-stop of enlarger lens, time, grade and paper-developer combo. Also if I did any burn or dodge, for how long and at what grade. Once the print is dry, I might add whether I think the print is good/bad/ugly and what I could do to make things better if I ever want to print it again - which believe it or not does happen. Not that often, it has to be said, but sometimes when you look at a print for a while you think it might warrant a second chance. Finally I would put a sticky with the neg code on the back. The print either lies around my desk for a while, goes on the wall/piece of furniture or else I file the print¬es with the negative.
It sounds like a lot, but it only takes seconds to do.
Is this all too much? Probably. Definitely. I was organised once, y'see - but that feels like a long time ago now and I don't like to talk about it any more.
I haven't always done these notes, but since I've been spending more time in the darkroom recently than out and about taking snaps the note-taking thing has kind of become more important to me (as you can see). Perhaps I'll reach the stage where I can just look at a neg and know instinctively what time and contrast it needs under the enlarger, but I'm not there yet. A looooong ways away, as they say in the States. So in the meantime, I think the notes help.
Last Saturday morning, for instance, while Missy was in orchestra, I spent some time in the darkroom, as one does when one has the house to oneself. The first hour was good, the second less so and by the third hour I was running out of energy. So after a bit of washing of prints and tidying up I made some green tea, sat down and looked through my negatives and read some notes and looked at some prints and...well, it all seemed to make a little more sense than usual. Yes, I know - very strange...