Good question - just some weeks ago I summarized my personal method/approach on tech research: https://www.alp54.com/posts/awesome-tech-research/ Further getting in touch/playing around with technologies (prototyping, etc...) might help to get here as well.

"The best way to predict the future is to invent it." - Alan Kay

Historically, I seem to have an accuracy of about 60% in determining when something new on the scene will be important or not. Better than chance, but not by much.

Just keep reading.

Effort and time spent are the secrets.