I have been looking though all the news articles about the recent CSS feature. Studied all the tutorials, and gave them all a thought.
And they are good. Some are catering really good dA specific tips, but down to earth - when it comes to CSS - all you need is this;
#1 - Rookie: Key in your preferences, and create your own standard. Go HERE.
#2 - Interested: Get to know dA CSS-standards HERE.
#3 - Hardcore: Customise to suit your needs. Go HERE.
Now...I hope this will help you. Myself, I had good help from these links.