Personal experience is also very simple. The premise is to make full physical and mental preparations and practice on your own according to everyone's situation. During the valley, in fact, don't dwell too much on the form of taking orally, communicate with your body more, understand your state, and adjust it in time. What suits you is the best, and don't care about the result. If you feel good, spend more time; if you feel bad, it's over. In short, let nature take its course and welcome.