Helpful Hints For Using Your Crockpot. 1. To avoid breakage or cracking, never add cold water to a hot crockery insert. If you want to soak the hot pot immediately after the cooked food has been removed, add hot water to the hot insert. 2. For best results, most manufacturers recommend that the slow cooker be half to three-quarters full. Refer to the manufacturer's instruction book accompanying your pot. 3. Keep perishable foods, such as meats, poultry, fish, and vegetables, refrigerated until preparation and cooking time. If you opt to cut up vegetables or meats the night before you're planning to cook them, be sure to package each different item separately and store in the refrigerator. 4. Purchase roasts and other large cuts of meats in a size and shape that will fit conveniently into your slow cooker. Otherwise, plan on trimming the meat to fit. 5. To end up with the least amount of fat in finished slow-cooker dishes, use lean meats and skinless poultry, well trimmed of fat. 6. In general, avoid using completely frozen foods in the slow cooker. If necessary, thaw frozen ingredients in a microwave oven before adding to the cooker. 7. To avoid heat loss, refrain from removing the lid during the first three-quarters of the cooking time. If you peek often, an extensions of the cooking time may be required. Remove the lid only to stir food or check for doneness. 8. Use cooking times as guidelines. Pots vary; each one is not exactly the same, and fluctuations in power or voltage may occur. Generally, figure that 1 hour on high is about 2 hours on low. Some recipes should only be cooked on high or low, so follow directions carefully.