At the Harvard Business Review, an interview with Frank Saucier, executive and Agile coach:
I use a quick feedback approach called Plus/Delta at the end of a busy day, after a key event, after teaching classes, after facilitating events, etc. I basically pull out a piece of paper and draw a line down the middle. At the top of the left column, I put a plus sign. At the top of the right column, I put a delta symbol to represent change. In the plus column, I write down all the things that I did well and that went well. In the delta column, I write down all the things I would do differently in hindsight. It’s basically a reflection technique for learning and quickly getting closure.