1. No matter what, write what I want to read. Connie Willis told me once, "Remember what you liked about science fiction in the first place." That means to me that I should tell the stories only I can tell. Don't worry about what anyone else is writing. Don't worry about what I think is currently popular or selling (besides, whatever looks popular to me now was what was popular with editors six months to a year ago---who knows what they want now? Why not make it what I'm writing?)
2. Write consistently. Don't do something stupid like let two months go by without actual writing happening. Those are not only two months that I will never get back, but also writing is about learning and growing. I'll be two months behind where I could have been in growth too. Writing consistently will have the added benefit of making me think about writing consistently. Someone asked me where my ideas come from, and the real answer is they come because I'm consistently thinking about writerly concerns. I don't sit at my computer and then say, "What should I write about?" I always have the flickering of an idea ready to go.
3. Read as a writer. Go back to the work I really admire and read with the idea of learning from a master. Writers have the advantage of being in a profession that allows them to apprentice to anyone. If I want to learn at the knee of William Shakespeare, I can. If I want to enter a dialog with Ray Bradbury, I can. All I need to do is listen to what the writers I admire have to say (through their writing) and take notes.
4. Be brave. Take risks on the page. These can be risks with language, risks with plot, risks with theme. No matter what, don't write stuff that feels "safe" because I want to avoid criticism or because I've been praised for telling that kind of story before. Remember Neil Young. He's never done the same album twice.
5. Be kind and reach out to other writers. If I read something I like, write the author and tell her so. It's amazing to me how isolating this profession can be. I remember when I published my first story in Analog. I thought, "Oh, my god! I'm famous." Hmmm. Not the case. I loved it though when an established pro sent me a e-mail later saying he liked the story. That meant a lot to me. The writing world is small, really, and there aren't many folks in it. If we aren't kind to each other, who will be kind to us?
6. Be thick skinned, but listen. I got a rejection once where the editor scrawled at the bottom of my cover letter, "Why don't you try telling a story next time." I laughed it off, and then looked at the manuscript again to see if I'd actually told a story. I had one story that was bounced 39 times. About half the time the editors who responded to it said that the story seemed "slow" or "long" to them. I used Ken Rand's 10% Solution on the piece, lost about 1,400 words out of a 7,700 word manuscript, and sold it to the next market. This gives me resolution 6a. Learn quicker.
Now, if I had just drawn up this list of resolutions in 1983, when I really started thinking of myself as a writer who was trying to write publishable work.