To match the number of novels, letters, essays, and other scribblings Asimov produced in his lifetime, you would have to write a full-length novel every two weeks for 25 years.
Holy crap! How did he do it? Have a read. There were 6 tenets to his approach, but to understand them properly - you really should read the article.
- Never stop learning
- Don’t fight getting stuck
- Beware the resistance
- Lower your standards
- Make MORE stuff
- The secret sauce