Taste of Home Slow Cooker Tips

I get the Taste of Home email and this was in one of my emails.  I really like cooking in my slow cooker, put it on in the morning and then forget about it!  Thought this was interesting and helpful to know.
Tips for Using Your Slow Cooker
Fill
To cook food properly and safely, manufacturers and the USDA recommend that the slow cooker be filled at least half full, but never more than two-thirds full.
Leftovers
Slow cookers should not be used to reheat leftovers. Use a microwave, stovetop, or conventional oven to reheat foods to 165°.
Lid
Each time you remove the lid from your slow cooker when unnecessary, you should increase the cooking time by 20-30 minutes.
Old vs. New Slow Cookers
Some newer slow cookers seem to heat up more quickly than older ones. If you have an older model and your recipe directs to cook on low, you may want to set it on the highest setting for the first hour of cooking to ensure food safety.
Power Outage
Following a power outage of less than two hours, you can finish cooking your food with your stove or microwave. If it's been more than two hours or you are unsure how long the power has been out, discard the food.
Preheat
Many slow cooker recipes cook all day. It may be easier to place all ingredients in the crock the night before, then cover and refrigerate overnight. In the morning, place the crock in the slow cooker and select the temperature. Do not preheat your slow cooker.
Settings
Most slow cookers have two or more settings. Foods will cook faster on the high setting. However, the low setting is ideal for all-day cooking and/or for less tender cuts of meat. If your slow cooker has a "warm" setting, use it to keep your food warm until you're ready to eat it.
Slow Cooker Size-Use this chart to determine the ideal slow cooker size for your family:
Household Size Slow Cooker Size
1 person 1-1/2 qt
2 people 2- to 3-1/2 qt
3 or 4 people 3-1/2 to 4-1/2 qt
4 or 5 people 4-1/2 to 5 qt
6 or more people 5-7 qt

Hope this will be helpful.  I like cooking pork and chicken in a slow cooker.  I still haven't found the best way for beef though.