My UI "process"

What can I learn to improve the UI design level as soon as possible?
I think it is the easiest to implement in MFC first.
1. Window background replacement
2. The simplest button self-Painting
3. More complex menu self-Painting
Then begin to understand what is subclass, parent class, or understand some special effects with Hook.
Then, let alone the limitations of MFC/wtl to understand the principles of some interface libraries.

Maybe the last time you go back to the starting point, the best interface is the best interface, not the most beautiful interface.
Briefly Talk About the UI function:
You can use the program/system to accomplish your work goals through the UI (the interfaces provided by the Program/system to the user.
From the user's perspective:
1. Complete the work content as quickly as possible. (The process is reasonable and guides the user to complete the target, with at least input, the mouse moving shortest, fewer buttons, and a short wait time)
2. Caring. (What he wants the system to do, the system has already considered it for him .)
3. Trust. (He uses the system to reduce the chance of making an error. The system won't crash easily and can be restored if an unexpected power failure occurs)
4. Yes. (You can even know how to use this program/system through the UI without reading the manual)
5. It looks pleasing to the eye. (The importance is estimated to be less than the first four)
From these perspectives, the highest level is unattended. -- Well, don't take a picture of me. I'm doing automated industrial testing and control.
Ui:
User-ui-business logic (function ).
1. Functions (that is, business logic) are stable, and functions are not changed because of interface modification.
2. UI is decoupled. After function development is complete, the UI can be designed separately so that they can experience users and stay close to users.
3. Even html/mfc/winform/WPF/xtp/BCG/implementation on the interface does not matter. The goal is to decouple function developers from the user perspective.
The highest state here is decoupling. Everyone can focus on their own fields and provide the best interface for others, with the least impact on others and the least impact on others.