It's important to have a consistent system so you can find related stuff later! I label all prints with the negative roll+frame number.
I started with sequential numbering with a BW, CN, or CT prefix on the number to indicate what sort of film it was. I kept the cut film strips in Agfa glassine files that folded into a narrow paper envelope... those were numbered of course. I also kept a 4x6 file card for each roll with technical information on the date, gear used, development process, subject notes, etc.
In 1998 I changed the numbering system from sequential to date-based, YYMMDD with A,B,C added if there were more than one roll finished on that date. Negatives go in PrintFile pages, of which there's a nice variety of styles. No more file cards, now replaced by computer database with the same information, more easily searchable. All the cards have been transcribed to the database too. Scans are numbered to correspond to the negative file+frame number too. The fifth shot on a roll finished today would be numbered 051127-05. Under the new numbering, this all naturally sorts according to date order.
I really like being able to quickly find something I know is in there somewhere, so I go to some effort to prevent frustration.