By building hundreds and hundreds of circuits.
I have employed a number of people and even though they did not have University qualifications, they had all built dozens and dozens of circuits relating to their field of expertise.
Then a University person came along and wanted to write for my magazine. I said I would give him the parts for the project and he could build a prototype. "Oh, I don't do soldering." was his reply.
He wasn't hired.
Then another University person came along and I hired him. After 2 weeks he had designed the PC board and had it made. He then asked me to purchase the components.
He fitted them and all the wiring was back-to-font and the displays were all reverse.
When he made the board (It was hand made with tape in 1984) he didn’t realise he had to think of the track-work in reverse.
He didn’t show up the next day.
This is just to prove that the most important thing is to build things and not just “think” they will work.