One thing we do is to load a new dishwasher tablet immediately upon emptying the dishes.
Result:
If there’s a tablet: it’s dirty.
If there’s no tablet: it’s clean.
That's a nice trick. What we do is use a reversible magnet that says "dirty" on one side and "clean" on the other
I've often wondered why the dishwasher vendors didn't put a label on the little flip open door so that it actually said, "dirty" on the outside, and "clean" on the inside.
That's a good one. One I tend to do is, once I know i will run the dishwasher overnight, I will set it to run with a delay. That way, even if I forget to put in the last few items, it's going to run and I will not run out of clean stuff. (My dishwasher is fairly slow, as it's a built-in one and can't pop open to dry).
I'm fully convinced that dishwashers are a hoax. Doing the dishes manually is far more efficient, both in water used, energy and time spent. Things to consider: time spent determining if the item is dishwasher proof, time spent playing dishwasher tetris, time spent filling and emptying, time pre-cleaning before putting things in the dishwasher, time spent re-washing after it turns out that the dishwasher did not clean your as well as it advertised on the box.
I can do the dishes after a family meal just as fast, and with better and more consistent results en less water, than when using the dishwasher.
The stable state of our dishwasher is dirty: clean only lasts the fleeting instant a person spots it and immediately empties it.