I read that praise is not enough on its own. It has to be supported by some constructive criticism. In terms of teaching/training TaeKwonDo, this is important (as most of the students are children). Giving praise can be fantastic, but, it can be taken for granted if used too much. Then, it loses it’s value. For example, telling my students that they have a great front kick is good. But, how much better is it when I give them something to work on? Something to work towards? Straighten your back leg, curl your toes up etc. Hopefully, they don’t take every comment for granted and realise that I don’t just say these things, but that I mean them.