I was losing track of stratigraphy layers at a site in Arizona until I started marking each trowel pass with a different colored golf tee, and now I can actually see the soil change before I dig through it.
Wait, did you get that golf tee idea from that old field methods blog? I swear I read something like that years ago and thought it was too simple to actually work lol. How do you keep track of which color is which layer when you're like five passes deep?