You can to configure all aspects of how new cases are set up in the Account Default Template. These settings apply to all new regular cases and templates that are created in the account. Existing templates and cases are not affected. 

Go to Account settings -> Settings, at the bottom of the page under Advanced Settings choose Make changes to enable. Now configure your own default settings. 

You can make the same settings as on a regular case or template; add documents, configure parties and make settings to cases created from the template.