If I had to share one thing to lower your food costs, I would say a really good support system. This can be friends, family, facebook contacts, whatever but they should be local to your area.
My support system helps me in two ways - we share meals and we share information.
Sharing meals: Our meal sharing began several years ago when my mother decided we needed to have family meals. These meals were open to any family member or close friend. Each Sunday, one person would be responsible for preparing a main dish and everyone else would supply side dishes. It created a bonding moment for family member but also relieve the stress of having to prepare an entire meal on your own. When we moved away from my mom, we continued that tradition with family members who were close to where we currently live. We have extended it to Friday night movie night when we make a less formal meal.
The benefit of sharing meals is that you can stretch the cost of meal amongst other people and still have a great meal. We discuss what the main dish will be so that other's can plan their sides. Some weeks we have themes just to liven it up.
I have heard cases where several families get together and share meals on a daily basis. As nice as that sounds, I can't imagine having most of my dinners away from home. I like having my time at home so I can eat dinner in my pj's if I so desire. But if that works for you - build up to it. Start with once a week and see where that goes.
Sharing information: The one thing we, as humans, can't seem to grasp is that we can't be everywhere or know everything. We try but not successfully. However, one way to feel like that is to have a network of people who will be your eyes and ears. It's not uncommon for me to call friends/family and tell them about this great deal I saw at the store. They do the same for me. This network let me know that corn was on sale for .05 an ear earlier this week at a store I don't normally shop at. It was this network that introduced me to Bountiful Baskets. These are resources I wouldn't have discovered on my own but now I can pass them on. We, also, use facebook to share information.
I use this network for foraging. We teach each other where there are places to pick fruit or fish to extend our food budget (more on that coming soon).
The other thing I use my network for is sharing of overstock foods. Sometimes when we can a food we end up with so much that we couldn't possibly store it all, let alone eat it. That's when we share. Sometimes we get great harvests from our garden or foraging that it would be a waste not to share. We, also, swap recipes to use our harvests. Having a strong network of like minded foodies is one of the best resources you can have. Don't have a network - start building one. Start with close friends and family. Let them know when you find a deal, they'll think of you next time they find a deal. Food is a popular topic - let it come up and then make comments like "I wish I knew where I could find the best deal on..." or "I would really love to eat more ... but it's out of my budget." If anyone knows of a great deal, they'll share (or however they get the food).
For me, I'm always looking for creative ways to stretch the budget and I share. I'm not too proud to share my blackberry picking spot or to ask someone where they find huckleberries or mushrooms. I won't learn if I don't ask. I hear that many foragers are hesitant to share where they forage - more often than not those are individuals who forage for profit. Those who forage for themselves are more than willing to share, more often than not. (oops - I will probably repeat all that when I talk about foraging next week).
Last bit of advice for today - don't hesitate to ask for help! Everyone eats and most people cook. We all come across problems or issues when it comes to preparing inexpensive food for our families. Whether it's the kids not liking what's for dinner or not being able to provide enough fresh vegetables, someone you know has a solution or an idea to help.