simplest of all: put in some chicken quarters. (They have some of the gizzards in them.) Cover and turn on. When you can smell it through the room, it's at or near done. Spice at table, I often use Louisiana hot sauce. Eat until full, especially if you've lifted weights and have 'earned your protein' for the day.
If you've added no water, etc, then the topmost exposed pieces will actually get browned (if you're not worried about the Maillard Reaction).
Or do the same with a boneless pork roast or country ribs. I have done chicken tenders this way, too.
You can also put in yams, etc - but they take less long to cook, so you add them later than you added the meat.
The most effort required is cleaning the crockpot.