I have a series of codes filed into the lower flip out lip of all of my double cut film holders.
Square notch is tens, half circle if five, vee notches are ones.

The number corresponding to the code is written on the memo field or dark slide edge of the holder with a balck sharpie permanant marker.
The number code becomes a visual shadow on the film edge of the holder it was exposed in.


I have three standard empty 4x5 boxes I take when travelling and will be reloading holders.
They are labelled N-1, N and N+1.
I also have a piece of dud 4x5 film in each package, with all the corners cut off a bit.
I put this piece between the first round of films and second round of films when I reload the holders more than once on a trip.

Using only one or two b&w films in 4x5 really helps with the clarity of this process.
I tend to put unloaded 100 speed sheets at the back of the stack in the say the N box and 400 speed films at the front.

Once home, I then feel for notch codes when loading the tank to process, to keep them separate.

I have a voice recorder, with a small prompt card glued and laminated to the front of it to remind me what to record, wrt location, meter suggestions, actual camera settings, filters, film holder and film used etc.

I did a big portrait shoot last week on old ortho film of a crew of boy scouts and had them process thier own negs as a part of the meeting. Used flash for consitent exposure.
To do this quickly I needed to round up all of my holders.
Turns out I have a lot more than I originally thought. Where did I acquire them all?
I have at least 15 double holders in pretty good shape, and a half dozen more dodgy ones that need hinge tape fix up loving, etc.