Saving Money on Groceries

I'm currently trying to go for a month without buying groceries. We have a lot in our pantries and even in the fridge and I think we should be able to do it without much trouble. I'm allowing for stuff like milk and bread because that just isn't feasible.
I've been trying to do my best to save money on groceries in any way I can because that's where a huge hunk of our money goes. I've recently joined a coupon train to try and cut some costs, so we'll see how that goes.
These are some of the tips I've been following to to reduce the grocery budget. So far, it seems to be working well. I just need to refine it, I think, and stick to it.