I took a 20oz drink bottle, cut the top off and filled it with CYA until it weighed whatever it took to add 5ppm to my pool. I made a mark, and then cut the bottle down at the mark so I have a measuring cup for CYA. Wrote "One scoop adds 5ppm" on the side so I never have to think about it.
Another thing I did was to write an "operator's manual" for my pool. Includes chemistry instructions and amounts normally needed, equipment instructions (valve settings for vacuuming etc.), cleaning instructions, where I keep things, where to buy stuff (like muriatic acid), things not to do and more. That way if I get sent away for work or when we go on vacation, whoever is taking care of the pool has a reference to fall back on if they can't get in touch with me.