Dream up a good, fun, interesting story that your readers will like, and that you will enjoy telling.
Readers can tell when the writer is having a good time.
Have at least one likeable character, and preferably several.
Villains can be likeable.
Show, don’t tell.
Avoid lazy words.
Make a general plan and fix it up as you go.
Spend time on research, and accumulate a research library built with real books. Put the library in your office near your desk.
Get an authoritative, descriptive dictionary. You will need to do some hunting to find a good one. Mine is a Webster’s New International Second Edition from 1938. You can find them on eBay or Abebooks or the like. Don’t get the Third Edition; they start to pander and capitulate in the Third, and it gets worse after that.
Read, a lot. Read books and stories that bring you true pleasure.
Read books and stories published before the internet came along, and stories published after, and think about the differences between them. Which do you like more? Which will your readers like more? Stories in the age of the internet seem anxious, self-conscious, and less fun to me.
Write every day, when your mind is fresh.
Take care of yourself; get your sleep, eat right, get some exercise, and a good fuck now and then, for perspective.
Don’t get worked up about being a writer or a poet or an artist. Don’t worry about being smart. Just write, and read, and do your research, and make a good plan, and let your characters tell your story for you. The rest is up to the reader, and the reader is the only one who matters.
Trust the reader. The reader is smarter than you think.