Creating Sharetronix themes is as easy as in any other open source platform of this type. To create the theme you need knowledge of HTML and CSS at practical working level, and in order to make a really great graphics site/page you will need to be able to work with graphic editors such as Photoshop.
When you install your Sharetronix version you will find a folder "themes" in your installation folder. It contains the 5 themes that come with Sharet...