I have a 20 or so 4X5s loaded with Forma 200 and 2 35mms one with Tri-X the other with Kodacolor 200. Currently I am using Pentex auto focus with windows so I can see what film I have, if I am using my older 42mm or Konicas I keep a strip of masking tape on the back of the body with the name of the film and date I loaded the film. Couple of months ago I was cleaning some of my old 35mm I have not in years and found a Spot with a roll of Agfa 100 in it, I still need to shoot what is left and process.