Cook for the month, or the week.  For example, if your family enjoys spaghetti, take one day and cook the expected amount of sauce you might use over a one month period then freeze it in appropriate serving sizes.  This will make coming home from a long day and preparing dinner much easier.  Hamburger can also be browned and frozen in serving sizes.  When you are cooking with hamburger, just pull out the necessary size and add it to your dish.

Clip Coupons and plan shopping trips.  It is alright to go to three different stores in one day if purchase savings are more than travel costs, or shop at a store that will match competitor prices.  

Read more about it:

Slashing your Grocery Bill