For me it's all about mood and how much energy I have. Some days I'll happily hit three different stores (my local co-op, Trader Joe's and Safeway) and putter around planning meals as I find stuff that looks interesting or is on sale. Other days, I just want to get in and get out with the things on my list. And still other days, I just can't bring myself to do it.

For me what helps on the days when shopping just isn't going to happen is always having certain things in the freezer and cupboards (my bare minimum is: frozen chicken pieces, frozen veggies, tuna, rice and pasta) and so that I can put together something even if I haven't been shopping in a while.

Also, on days when the cupboard has gotten bare and I know I'm going to have to drag my ass out to the store and I'm all mentally whiny about it, I try to come up with some kind of reward, even if it's something small like getting a mocha or a smoothie somewhere.