The New York Times posted a conversation between Lin-Manuel Miranda and Stephen Sondheim that contains sage advice for writers of any kind.

Here’s Sondheim, talking about what makes a good collaborator:

You’ve got to have somebody who’ll surprise you and, you know, it’s the old lesson, you’ve got to work on something dangerous. You have to work on something that makes you uncertain. Something that makes you doubt yourself.

And Sondheim again later in the interview:

You shouldn’t feel safe. You should feel, “I don’t know if I can write this.” That’s what I mean by dangerous, and I think that’s a good thing to do. Sacrifice something safe.
Miranda wrote in the article that he corresponded frequently with Sondheim during the development of “Hamilton” and said Sondheim’s email response was always the same: “Variety, variety, variety, Lin. Don’t let up for a second. Surprise us.”