Frugal living means looking at every meal as a potential ingredient for another meal. I hadn't realized how efficient I had become at this until I went away for a week and came back to discover a fridge full of leftovers. The obvious solution to leftovers is to use them as lunches. However, if you've had something for dinner and then for lunch the next day, do you want to be able to recognize it in that night's dinner? Probably not.
Here's an example of how it works at our house. One night last week I made chili. The next night I made a gluten stew. The following night I combined the leftovers of both and added acorn squash and some spices to create an entirely new entree that we served with quinoa. There were no leftovers of this. That's one of the goals.
The important thing to remember is, make sure you're combining flavors that will blend well. When I'm not sure about this, I've been known to take a little bit of each on a spoon and taste it.
If you begin to think of leftovers as the base of your next recipe, you'll discover two things. First, you'll get your leftovers under control. Second, you're cooking time is likely to decrease a bit. If you're keeping track, you might even discover your food bill going down, especially if you routinely through out leftovers.