Open a project, preferably one with all the reference types that you'll later want to use in your paper.
On the Citation menu, click Citation style > Edit citation style.
Click Create citation style.
Drag components from the a list of components to the b rule set templates. For each c reference type you can set which components should appear in the bibliography, in-text citations, and footnotes. The d preview shows the results once the templates have been defined. Please note the rules of thumb for using components.