According to what you said, tension and relaxation in playing can be divided into two kinds according to my understanding. The first is that tension and relaxation coexist and can be used together according to the understanding of the work. The second is how to overcome the tension and how to relax to achieve better playing skills.

Now we don't care what you want to write, let me talk about how to make an outline (personal opinion). First of all, whether you write the former or the latter, the difference is that the tension and relaxation of the former are two mutually supportive relationships, so you need to explain the functions of tension and relaxation respectively and how to make better use of them to achieve better results. (You need to consult a lot of papers for relevant materials, so I won't introduce them here. That is to say, tension and relaxation are two opposites, and opposites are easier to write! Use examples to explain what will happen if you are nervous, and then explain what effect relaxation will have. Finally, you can write how to relax and achieve better performance!

"On the Tension and Relaxation in Piano Playing" or "On How to Avoid the Tension and Relaxation in Piano Playing"

1 the relationship between tension and relaxation in piano playing (explain whether it is antagonistic or interactive)

2 piano playing causes tension factors and consequences

illustrate

How to relax in piano performance, what better effect will it have?

for instance

That's probably what it says!

My wife is a piano teacher. I didn't! So just for your reference! You can read some books about how to relax your wrist! I remember a book "On Piano Teaching" by Zhu Gongyi, with a yellow cover! I've seen it. You can see that! There are examples in it! I can only help you with this! I hope it works for you!