I don't always take the time to do this, but I'm sure happy about it when I do.
BEFORE I go grocery shopping, when my refrigerator is at it's lowest inventory, I go through it and toss out any outdated or spoiled foods. I wipe out the drawers and clean the shelves and glass. This time I had just gotten back from being out of town for 9 days so there was precious little in the fridge. I took out the bins and shelves and washed them in the sink. (I rarely take it this far but the cleaning bug bit big time once I got started.)
THEN I go grocery shopping. It's really nice to come back and restock my very clean fridge! I'm including a picture because it's the best it's looked in a while and the best it's going to look for a while to come I imagine.
Works for me (when I do it)!
Check out other tips at Shannon's blog, Rocks In My Dryer.