1. Read some fortune-telling books to accumulate experience, and then read books on the basics of Yin-Yang and Five Elements. It is recommended to read Zhouyi, which can be written in vernacular. In short, you should stick to it.
2. Cultivate your mind and keep your mind at peace. It is not allowed to add your subjective thoughts to what you want to calculate.
3. You need a little talent. Oh, you can't force this.