A great way to save money is with a menu. You plan what you will eat for a week, or two or for a month. You then plan your shopping around that. There is very little impulse buying, you have your coupons at the ready, and you can doing some freezer meals easily this way.
I try to stick to a menu. But things do come up and I can't always make what I planned, which could lead to a domino effect. Some meals I plan to use left overs for the next day in another meal. So not only does it mess up that days menu but the next days as well. I have been making some frozen meals with our regular dinners. I will double the recipe then freeze half. This has been working out well so we don't have to buy prepackaged frozen meals for those days when I screw up. Manacotti, pancakes, breads, muffins, taco meat and stir fry chicken all make great freezer meals. And they taste a ton better than the frozen ones you can buy.
An unexpected positive a menu has done for us is to keep unnecessary junk food out of the house. Since I plan my shopping list around my menu I buy only what I need. If the kids decide they hate my meal they can make their own and shockingly they have been choosing healthy foods to eat because we don't have a ton of prepackaged food in the house.
Oh and yahoos alarm feature is a great way to remind yourself to thaw that meat or marinate that chicken. That annoying beeping from your phone? Time to make the donuts! Or whatever you happen to be making.