I feel like I haven't written here in a while. I feel busy, and busy makes me feel stressed. Actually, I think everyone I know feels busy and stressed lately. For me, being stressed makes me less likely to pay attention to my spending and forget my careful planning and/or budget and just go with the easiest thing that gets the job done (To hell with the expense.)
It's times like these that we (or at least I) need to remember to be frugal. If you know you have a busy week coming up, put the ingredients to an easy crock pot meal on your grocery list and make sure you throw the stuff in the night before you need to plug it in (and refrigerate of course) . Then the next day you aren't staring into that frozen tundra that is your freezer at 6 pm and decide that $30 takeout is a better (costly) solution.
Fortunately, when I get like this, I have some pretty well ingrained frugal habits to fall back on that I don't do too much damage. For example, it's just second nature for me to look at the price per unit (lb, oz, whatever...) at the grocery store, even if it's not clearly stated on the package. Even if I'm in a hurry I do that. I can't help myself. I usually get the best deal. I say usually because I really DO like Hellman's mayo better than Wegman's (Though if I'm feeling broke then you can be sure I'm bringing home Wegman's Mayo.)
This really isn't about grocery shopping as much as it is about being mindful of those things that cost you money when you aren't paying attention to them. You know what they are for you.
Just like any skill, it gets easier and more second nature the more you practice.
Now go and work those frugal muscles!