While I typically don't wear a lot of black clothing, one item I love is a basic black draped cardigan. It hides a few flaws, adds an extra layer of warmth and, when paired with coordinating accessories, it pulls an outfit together. Draped cardigans are also great for nursing moms.
I tend to stay away from black, because it easily shows that I have pets and kids. I have a few black pieces in my closet that I typically wear for date nights and funerals, but prefer charcoal gray or chocolate brown.