I like this list, written by Nat Ryall:
Here are some rules I follow:
- Try not to repeat content.
- Try to get linked from other, relevant and high quality websites.
- Try to make sure your outgoing links relevant to the content of your site (rel="nofollow" for ones that aren't, such as ads).
- Give each page a relevant (and unique) title.
- Add in a meta-description to each page describing the contents or purpose. Keep in mind that meta-descriptions are not used as much today.
- Mark up your site using schema.org and authorship markup, if applicable, to display rich snippets.
- Build a sitemap for your website and submit it using the Google WebMaster tools.
- Keep content unique and relevant to your website.
- Use HTML correctly (header tags, titles and alt attributes on images).
- Try to use relevant keywords in the URL.
- Ensure a fast load time.
Generally, if you follow these rules, your domain will naturally rank better with Google over time. If you try to speed this process up, using things like keyword spamming on your website, you are likely to be picked up and blacklisted by Google so avoid this wherever possible.