Rand B. Lee
(1) Write what you really want to write, not what you think will sell.
(2) Make your first draft a vomit draft: that is, pour it out of you without regard to spelling, grammar, punctuation, or future sales probabilities. Compulsive editing too early can bring on writer's block big time.
(3) Write something every day, even if it's just a suicide note.
(4) Never discard anything you have written. You never know if the piece you are tempted to discard might contain a gem of an idea or turn of phrase or theme that will inspire you down the road.
(5) Read omnivorously works by writers you admire. As you read, ask yourself, "What about this piece turns me on?"
(6) When you finish a piece, make a list of the top ten paying markets you think it's suited for. Then send it to the first one on the list. If it's rejected, send it to the second one and so on down the line. If everybody rejects it, get yourself a nice big Belgian dark chocolate bar and eat it (the bar, not the piece). Then start work on something else. You may find that time off from the rejected piece will pay off in the long run when you have sufficient distance from the piece to reread it and see what's wrong with it.
(7) Get a day job. We can't all be Stephen King or J. K. Rowling.