Emily Henry's advice for writers is short and genuinely hard to follow. The gist: read constantly, and finish what you start even when it's going badly. Most of it comes straight from her own FAQ and her interviews.

The Direct Answer
Read widely, finish every draft even when it's bad, fail fast after rejection, and write only what you can write.
Drawn from her official FAQ and her Writer's Digest essay on writing the second book.

Finish the Draft, Even a Bad One

Henry's most repeated advice is about finishing. She calls herself a huge believer in completing things, and she's clear about why. A finished draft, however rough, gives her something to improve. A blank page gives her nothing (her official FAQ). She'd rather commit to finishing a bad draft than guard a good idea she never actually writes down, because the writing is where the idea gets tested.

It is always easier for me to fix a book than it is to create one out of nothing.

Emily Henry, official FAQ

Read Widely, Fail Fast, Write What's Yours

Her second pillar is reading. Henry tells aspiring writers to read as much as possible, the books they love and the ones they hate, and to work out what makes the difference. The idea is that wide reading widens your taste faster than your ability can keep up, and the only way to close that gap is to keep writing through the stretch where the work falls short of what you can see in your head.

She's just as blunt about rejection. In Writer's Digest, Henry's advice was to fail hard and fast, since a rejection can knock a writer down for long stretches while they rebuild the nerve to try again (Writer's Digest). Shorten the time you spend flattened by a no, and you keep your momentum instead of losing months to it.

Henry also warns against chasing the market. Her guidance is to write what only you can write and what you genuinely want to write, whether or not anyone else is doing the same thing, and to remember that success in publishing is a separate matter from success in the writing itself. Trends move faster than books do anyway, so betting a manuscript on one is usually a losing trade. You can see how she lives these rules in the full Emily Henry writing routine.

What You Can Steal