Mistake number 7 is wasting time doing SEO tasks that you could do a lot faster. For http://seo.ijoomla.com example, every time you want to edit the meta tags of articles, you have to go to the Article Manager, find the article, open it, scroll to the bottom and enter the meta tags on the right. That can take a while, especially if you have a lot of articles. Get a bit lazy, like me, and you probably won't do it.