Never go shopping when you are hungry -- everything looks and sounds
like it would be
a good munch.  Make a list, of foods that you know -- and stick to the
list.

Spin marketing is done at the grocery store -- making you walk to the
back of the store
for that carton of milk -- sending you down aisle #3 clear to the
back--for that loaf of bread.
What's across from that bread - cookies.

Being a smart consumer takes practice - learning to stick to a list,
and sticking to it.  This isn't
to say you should try new products, but be very label conscience,
what's in it---if I cannot read
or pronounce the ingredients, then I usually don't buy it until I
learn more about it---fresh is always
best, and homemade or homegrown is even better.