The first is the technique, that is, how to write, writing skills. For example, many techniques such as inverted pen, inverted pen, side pen, offset pen, virtual pen and inverted pen are well written, but they are not techniques, which is one of the reasons why many people can't become calligraphers if they write well.
The second is composition, that is, the method of planning the layout of the article. The same text, different layouts will have different effects. For example, the writing of horizontal couplets requires neatness, but it is not necessary to emphasize these when writing a word. In addition to the overall layout, a calligraphy work should also emphasize the methods of reality, size and relaxation. Generally speaking, when writing running script and cursive script, it will be used more, while writing regular script, seal script and official script is more neat.
Besides the above, the experience of writing is also very important. The artistic conception of the words written by an educated and open-minded person will be very different from that written by a craftsman.
I hope the above answers are useful to you.