We are leaving town this evening to spend Thanksgiving with the married kids (and Arwen's in-laws). But because of a scheduling issue, we won't be able to leave until later evening. So tonight is leftovers night.
I know that in some families leftovers have a bad reputation. I know of one where Mom eats all the leftovers for lunch because no one else will touch them. But our leftovers night is (relatively) popular,because everybody (usually). gets to choose something they really like.
On the morning of leftovers day -- I schedule them into my menu plan -- I go through the fridge and make a complete list of what's in there. (I try to keep all leftovers in one area, with varying success.) I mark down approximately how many servings of what are available. Then at the bottom of the page I list everybody who will be around for dinner, and plop the paper on the kitchen table. As people select what they would like, they write it on the list after their name and cross out the servings or items they chose. (Obviously, when the kids were younger I helped them with this.) Then, come supper time, I organize and heat up what's wanted, and throw away the rest.
I can't promise this method always makes everyone happy -- Roger somehow often winds up out of town on leftover night, unless there's meatloaf -- but most of the family is satisfied, and there are no mysterious tupperware science projects in the back of my fride. And that's a success!