If you can't tell the difference between your ice cubes and your ice cream, it's time to throw BOTH out. Yogurt is spoiled when it starts to look like cottage cheese.
Cottage cheese is spoiled when it starts to look like regular cheese.
If opening the refrigerator door causes stray animals from a three-block radius to congregate outside your house, toss the meat. Fuzzy and hairy looking white or green growth areas are good indications that your bread has turned into a pharmaceutical laboratory experiment. You may wish to discard it at this time, depending on your interest in pharmaceuticals. It is generally a good rule of thumb that cereal should be discarded when it is two years or longer beyond the expiration date, or when it will no longer fall out of the box by itself. Flour is spoiled when it wiggles, or things fly out when you open it.