Of late Robert Heinlein’s legacy as one of the great postwar science-fiction writers has been somewhat forgotten, or overshadowed by his status as libertarian icon. But he deserves recognition not just for his great novels (Starship Troopers, Stranger in a Strange Land) but for providing us with some of the most salient writing advice ever put to paper.

In his frequently cited article, “On the Writing of Speculative Fiction,” Heinlein laid down five solid rules:

1. You must write.
2. You must finish what you start.
3. You must refrain from rewriting except to editorial order.
4. You must put it on the market.
5. You must keep it on the market until sold.

The last is particularly helpful for writers who have a difficult time with rejection. Of which there will always be a lot.

Heinlein was also smart enough to acknowledge that he frequently broke these rules himself. But sticking to them will help instill the diligence, rigor, and stubbornness necessary to get anywhere as a writer.