You can learn an amazing amount about how to write science fiction from reading Robert A. Heinlein. And like many authors, he produced a list of “rules” that helped him sculpt a career that reflects the times in which he lived, and create a reputation that took him to the top of many reading lists in his chosen genre.
1.) You must write.
2.) You must finish what you write.
3.) You must refrain from rewriting, except to editorial order.
4.) You must put the work on the market.
5.) You must keep the work on the market until it is sold.