2. Writers write. Having a tough writing day? The writing blues got you down? The best cure is to write. Sounds simple, but it's often not. It's so easy to let "writerly" activities consume the time we need to putting words on paper.
3. Set goals. Whether they be word count or time goals, try to set them. I struggle with this one often, but I know I would be so much more productive if I obeyed it.
4. Never stop reading, or learning about the craft. Never let yourself think you've finally "arrived". You never will. And that's not a bad thing. It's what makes this writing life so rewarding. You can always write better.
5. Find the Joy. Remember why you first started writing. Was it because you love the written word? Because a story burned within you, and you had to let it out? Try to think about those times. They'll encourage you when things aren't going quite as you planned.
And for good measure, here's a 6th: Patience is key. The waits are often long and arduous in the writing biz. Come into it knowing that and you'll be just fine.