I don't know if this is super creative, but any leftover that I've ever had is a billion times better in the air fryer and not the microwave. And so it's not like creative how to use leftovers, it's the best way to taste leftovers and investing in an air fryer turns all of your leftovers into the like the original meal itself and that's a hack.
I've never tried this before but I heard that you can make a Thanksgiving leftover sandwich.
I like to take leftover pot roast and make french dip sandwiches. Slice it thin and just get the packet au jus and toast the buns. Tastes really good and quick and easy and fast.
When you're cooking things that are good to be cooked, like you can cook in bulk, or that are good to be saved in the fridge and reheated for leftovers, make a lot of those. Like, for example, if you do like ground beef and rice, you can end up making that into a lot of different things. Or if you cook chicken, cook extra chicken, and then you can either do that and like have a bowl the next day of it or a burrito or whatever. You can just do those things in bulk and end up just switching up how you eat it the next day or the day after.
Leftover spaghetti and leftover mac and cheese tastes really good fried up with eggs, especially if you add cheese on top of it.