Like some of the others, I like to process a bunch of rounds in steps. I have 4 bins, labeled raw-fired, tumbled, decapped/resized and primed, for each caliber. I can do as many as I want from any group whenever, without the pressure of finishing a tray, with the sole exception of setting the bullet after throwing powder.
I love the fact that I can squeeze in 15 minutes here or there to process another small group of brass. My wife appreciates that too.
This is supposed to be an enjoyable part of the hobby!