I got a chance to talk to Yang Jun about your question yesterday. I will summarize his response here. He said this is a very hard question to answer. A lot depends on the cultural viewpoint. From a Chinese perspective, he would probably stress the primacy of morality, and how it comes before the martial component. In the west, and to a great extent in China too nowadays since taiji has become largely a health exercise there also, he said if he had to boil it down to only one piece of advice, maybe it would be the necessity to be persistent, and practice regularly.