I look at our social calender and work schedules to see what nights we will be able to eat together and then try to make sure I can use the leftovers from an early day in a meal later in the week. It is easy to have leftovers when you're only cooking for two. If you're cooking for a larger family you might need to plan to cook extra. It seems like a lot of work up front but it's soooo great to know that I have every ingredient for dinner and when Chris says, "What's for dinner?" I don't have to groan.
We made shrimp tacos with citrus slaw yesterday for labor day, seriously one of my favorite recipes. Check it out, it's so easy and delicious. Plus I don't measure any of it! I served it with watermelon which was only $4.49 for a half seedless watermelon at Freshfields Farm, compared to $3.45 at Publix for a quarter seedless watermelon.
We had some slaw leftover and no shrimp, but we had 1 small grilled chicken breast leftover from "Dinner Chris Style" so I had grilled chicken tacos with citrus slaw for lunch and nothing got thrown away.
If you're going to worry about getting the best price, don't throw away food! Make sure you can use all of something before you purchase it. The only downfall is that we have a tendency to have themed weeks. I use broccoli 3 times during the week to make sure we eat all of it. It's broccoli week! Maybe if you have kids you could use it as a learning opportunity. During dinner you could talk about all the cool things broccoli does for your body (or maybe I'm nerdy).
There are a TON of websites out there to help you with meal planning. I can't really recommend any of them because I don't use one. Do you use on that is great? Please share if you have one, I found this super cute visual aid to help you remember to have balanced meals.