1. Be authentic. Readers can sense when you are forcing a character, an event, or even a setting. Write honestly and organically even when it seems risky or too raw. Authenticity wins readers.
2. Write through emotions. Often, when I am writing a scene that evokes strong emotions from my characters, I am living those emotions. This is when I often feel like a crazy person writing through sobs as a character experiences tragedy or heartbreak. I've learned that the scenes I cry writing are the ones readers say brought them to tears as well. Don't be afraid to write with your heart wide open.
3. Fiction is the greatest escape. I tell readers (especially when I speak at schools) that you can write yourself anywhere and you can read yourself anywhere. Allow for the escape. Let the fiction be as far from your truth as you want. I try to write stories I would enjoy reading and when I ask myself why I enjoy a certain work of fiction, the answer I find myself repeating is that I am able to dive into the story and escape my own reality. Give the readers a vacation from their lives by taking them away to the world you create.
4. Walk away from your writing and return to it. There is no better advantage for me than looking again at my own work with "fresh eyes". Writers can become so enveloped in their stories that sometimes what we think we've said is still in our heads and not on the page. Step away from your work every once in a while and return to it to re-read it with fresh eyes. You will be floored by what you discover is missing or needs changing.
5. Don't be afraid to trash something. It doesn't matter if I spend weeks, months, even years of my life on a piece of writing...if I decide it's no good, I trash it. I don't consider the efforts put forth as a waste, but rather as a cathartic part of the process to rid my brain of unneeded ideas to clear the path for better ones. Good writers know what's going to stick and what needs to be forgotten.