Prepare for acceptance, not rejection
Jeff Shotts has a more positive suggestion for writers than the typical “prepare yourself for rejection” spiel.
Shotts, the executive editor at Graywolf Press, says instead that you should prepare for what happens after your manuscript is accepted.
In particular, you’ll want to understand how a publisher will talk about and present the book.
And you’ll also want to familiarize yourself with the editing process and ensure that it’s a conversation, not a monologue.
Shotts explains this advice in further detail at Poets & Writers.