My top tip is to just make vast (or at least double) what you normally do, and freeze the leftovers...one lot of effort for two (or more) dinners.
That American Mom style thing where you bag all the uncooked ingredients does work. I just adapted recipes I already did, with the exception of pre cooking the onion/carrot/celery mix first....I hate slow cooker food when that is not done, imo that's where the damp sweaty not properly cooked taste comes from when folks complain about slow cookers
I also didn't put in thing like tinned toms, or beans....they are already in tins so you can just put them in when you are ready to go, brandishing a tin opener is hardly a chore
I went with a Spanish chicken thing....so soffrito, chorizo, chicken, plenty of S&P, crushed garlic/oregano in freezer bag.....hurl in chick peas, passata, tinned toms and maybe some chicken stock when you put it in the slow cooker
Country Chicken/Pork.....again with the soffrito, meat, big chunks of apple, great big dod of wholegrain mustard, big pile of chopped carrots, and sliced leeks into the freezer bag, and then add cider/stock when it goes in the SC
Paprika Beef, Beef in Beer, Chicken Curry type effort, Spicy Pork & Beans ....basically any one pot style recipe can be done.
You get the gist! ...the only issue I had was remembering to defrost the bag!