Create new site style based on existing, a must!
This is a must, otherwise your site will change in looks if you make a change in another site sharing the same style. By creating a new style for every site project you eliminate the possibility of making changes to older site projects accidentally.
Understanding Fusion Styles and Templates New for 2003. This article covers the differences between Styles and Templates in NetOjbects Fusion. You can also learn about using Custom Styles and Templates like those available in the gotFusion Store.