1. Keep the same out-dated pages on the website for months or even years
2. Not using unique title tags for every page
3. Keyword stuffing your content
4. Using too much Flash in your website design
5. Using too many images and not optimising any of them
6. Not using keywords correctly
7. Strange characters in your URLs
8. Black Hat SEO tactics
9. Link to questionable websites
10. Excessively linking to other websites
Learn more:
Networth Media