There are 8 stylistic module class suffixes which provide a unique style variation to the module: title1-8 and box1-8. There are also various additional structural suffixes, these affect the layout and metrics of the module.
Furthermore, you can also add FontAwesome icons into the Module Class Suffix. You will get a medium sized icon to the left of the title. Suffixes are in the icon-NAME format such as icon-star, as shown on the Typography page.