If it's not something my family has tried before and I don't know if they will like it I just serve it to the table and everyone takes a small bit to try out so they don't end up with a large plate they won't eat. For the most part my older kids and us parents will eat one meal we don't like unless we really are just not hungry... but at younger ages the kids all seem to go through periods of 'difficulty' where they will insist they need food but absolutely refuse the food available to them (even though the day before it was their favorite
). If there are a lot of leftovers and no one likes it I will freeze the extra in single servings for 'emergency' meals because someone will eat it if they are hungry enough and there's nothing else or they need to head out for the day fast unexpectedly and need something to take with them. I do pack leftovers from our plates in my husband's lunches. He's always enjoyed finishing off our plates though (he will actually wait out going for seconds of a meal to see if anyone can't finish theirs first). I also sometimes save the kids' leftovers for my breakfast, it's nice to have a hodge podge of a few bites of stuff to eat for myself when I get up before everyone else so I can take my time and make a big breakfast for them, plus I don't really like the standard 'breakfast' type meals that the rest of the family enjoys.
It can definitely be a challenge not to fall into the thinking of just a little bit of food left on a plate which seems like not enough to save for later but would be such a waste to scrape into the garbage but I really try to remind myself that I am always modeling behavior for my children and it isn't healthy to keep eating past fullness. The other day my husband actually caught himself saying to one of our kids, "why don't you finish what's in your bowl, there's only a bite or two left"... why do we do this? Whether someone that is full eats it or it goes in the garbage, since it isn't providing sustenance it's still a waste, better to waste it in a manner that isn't also contributing to future health problems. I have these very small pyrex containers and whenever I find myself tempted to eat something just because there's so little left I just put it in one of those containers and save it for later. It might make it's way into the garbage later anyways, but at least it doesn't get 'waisted'!