When still a child, make sure you read a lot of books. Spend more time doing this than anything else.
When an adult, try to read your own work as a stranger would read it, or even better, as an enemy would.
Don’t “romanticize your vocation”. You can either write good sentences or you can’t. There is no “writer’s lifestyle”. All that matters is what you leave on the page.
Avoid your weaknesses. But do this without telling yourself that the things you can’t do aren’t worth doing. Don’t mask self-doubt with contempt.
Leave a decent space of time between writing something and editing it.
Avoid cliques, gangs, groups. The presence of a crowd won’t make your writing any better than it is.
Work on a computer that is disconnected from the internet.
Protect the time and space in which you write. Keep everybody away from it, even the people who are most important to you.
Don’t confuse honours with achievement.
Tell the truth through whichever veil comes to hand–but tell it. Resign yourself to the lifelong sadness that comes from never being satisfied.