If I go on a photo trip I number each roll, for example H1, H2, H3, H4, H5 etc for all rolls shot with the Hasselblad. P1, P2, and so on for pinhole. L1, L2, L3 for the Leica.
Then I carry a note book and write down the pertinent info like lighting conditions. Works for me! I like the idea of taking a picture of a note with 'place, time, people's names, etc)
Permanent markers are unreliable if the film is going to be handled a lot, so I write details on (fine point DVD marker) a piece of narrow masking tape and secure the leader / roll end with that. That piece of tape then is attached to the job sheet on return from the lab so I know everybody has seen it.
Scratching is exactly what I did the last time. With a knife, I wrote a terrible 8. ..
My Color film is developed by my local shop, and they cant push C-41, just pull so I just shoot it at 200.
I think I will start taking notes on my Iphone on important shots. But
One of the things I like is to develop a roll and not knowing what will come out, but perhaps it is worth it in the end to know some of the settings and when/where the shot was taken.