Read the comments too.
I've managed to trim my personal food waste by developing a few good habits.
When the sliced deli meats or cheese isn't used up in a week, the extra goes into a bag in the freezer. Perfect for topping a pizza or toasted sandwich. And when I open the jar of sauce for that pizza, the rest of the sauce is frozen in single size servings. Best investment ever though is 'Keep it fresh' produce bags. I was skeptical the first time I saw them, but they really do work. I've kept fresh broccoli looking fresh for over a week. Even romaine lettuce stayed nice for 7-10 days. These bags pay for themselves by cutting my grocery bill.