1) Don’t install any sample data when you set up a Joomla! site.
2) Your Site Name should be your site’s name.
3) Turn off your PDF links.
4) Don’t waste your site’s link juice with lots of social bookmarking links.
5) Redirect the www and non-www versions of your site to the same place.
6) Turn on your cache.
7) Enter a full description for all your sections and categories. Do not forget to fill in Meta Data.
8) Less is often more.
9) Empty your global configuration metadata.