I’m not sure if everyone else already knows this, but when I went to reheat my roast chicken, I decided to do it in the toaster oven to see if I could crisp up the skin. I put a fairly large chicken breast or thigh quarter, covered with as much skin as possible, on a toaster oven baking sheet at 350 for 1/2 hour without preheating. The skin isn’t as nice as from a fresh roast chicken, but it did crisp and taste good. It’s a nice technique since I usually cook for one.