Are you a writer when you're not actually writing?

Yes.

Here's why.

When someone asks "is there a doctor in the house?", the answer is never "well, that depends. I mean, if you're just enquiring casually then no, I'm not doing any surgery at the moment. But if you actually need a medical professional, yes, I'll become a doctor as soon as I start work."

If you phone the plumber and say to the person who answers "is that the plumber?", they're unlikely to respond "no, I did some plumbing this morning and I'll be doing some more tomorrow but right now I'm talking on the phone."

Always have a product that's not just 'you'

...you should always have a product that's not just 'you'. An actress should count up her plays and movies and a model should count up her photographs and a writer should count up his words and an artist should count up his pictures so you always know exactly what you're worth, and you don't get stuck thinking your product is you and your fame, and your aura.

Andy Warhol, Fame

Always find the 'why'

From 'The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win' by Maria Konnikova:

It’s only a few months ago that [poker player] Phil Galfond reminded me to always find the why behind every move, every decision, every action. And here’s one thing I know for sure: no matter the decision, the why shouldn’t ever be for the simple glory of saying you’ve done something. At least to me, right now, that’s not good enough.