I would just also like to add

- Choose your subject of expertise and stick to it
- Post regularly, daily ideally. This is preferred by readers and search engines
- Always try to be interesting, rather than regurgitating news from other sites.
- Encourage a community feel

For example, I love my celebrity gossip sites. There are dozens of them covering the same news, with the same pics. Why do I visit some and not others? The best ones are witty and updated daily, and also the comments posted are wittier than average....