General Cooking Questions

What is your best method of warming up those left overs? Pretty sure this is more of a home use type activity, and if your like myself it seems you always cook more than can be eaten at one meal. Thus left overs and how to use them. How to warm them up without over cooking (through this re-warming process) them more than necessary to be served again or mashing/mincing etc. of the food beyond recognition.
Red Meats (includes steaks, roast,chops, ribs, burgers, meat loaf,briskets, etc)? This is the area that most of my wanting to warm up the item may occur.