Ask Celeste Ng how to write and her answer is short. Read a lot and write a lot, then tell the stories that actually matter to you. She's also blunt about writer's block, which she mostly doesn't buy.

The Direct Answer
Read widely and write often, and tell the stories that matter to you before worrying about audience or platform.
Her core advice, in her own words on her site's FAQ, comes down to reading a lot and writing a lot.

Read a Lot, Write a Lot

Ng's advice for new writers is deliberately basic. Read widely, including things you love and things well outside your comfort zone, the way you'd taste an unfamiliar dish. Write often, and treat it like an instrument or a sport that only improves with practice. She frames both as feeding the same engine, since she doesn't think good writing happens without a lot of reading behind it.

Tell the stories that are important to you. Write the stories that you'd want to read yourself, the stories you need to tell.

Celeste Ng, celesteng.com FAQ

She takes reading seriously as craft, not just as pleasure. Ng has talked about trying to learn from everything she reads, whether or not she enjoys it, in the spirit of being a reader on whom nothing is wasted. Even a book she doesn't finish can hand her an idea or a technique she files away for later.

She extends that to publication. Whether a story gets published isn't the measure of whether it was worth writing. In her framing, writing it down is the part that counts, and the audience comes later.

On Writer's Block and Characters

Ng doesn't really believe in writer's block, at least not as running out of ideas. When she feels stuck, she reads it as a signal that she needs more input. So she rereads her manuscript, reads other writers, takes a walk, or goes and learns about a new subject until the work starts moving again.

She builds characters the way you'd meet someone at a party. She gets to know them well enough to sense what matters to them and who they are, which is why she writes far more about them than ever shows up on the page, then trims what the book doesn't need. On career, she's clear that the work comes first, and that a platform is frosting that can wait. As demands on her time grew, she's said learning to say no became an important lesson, a way to keep promotion and everything around the writing from crowding out the writing itself. For more, see the full Celeste Ng writing routine.

What You Can Steal