about two years ago, we went to a dave ramsey course at a friends church. like dave ramsey, or not, it has been GREAT for our family.
we do not shop once a month, rather walk to the little store close to our house & get the things on an as-needed basis. this is usually several times per week. i take my two kids with me (one is a baby) & i let my toddler pick a snack from the bulk bin (i.e. yogurt covered pretzels, banana chips, etc.) & he only gets to get a few pieces. he likes it because he gets something different most times & i like it because it might add $1 to the total bill & we don't have junk food to bring home.
i have found that this frequent shopping saves us more money than the monthly trip (which we tried for several months) in that there is NO WASTE. no cans sitting in the pantry & food is always fresh. the walking there is also good exercise & doesn't make me experience the stress of the huge trip with the massive unloading once home.
good luck with your frugal lifestyle! we are having a great time & are ALMOST debt free :) hang in there!!!