When creating new entities, you can create one based on a template instead of starting from an empty form. To set an entity as a template, view it and click on Set as template in the actions button on the top right. When viewing a list of entities, templates of that entity type will be available next to the button. You can have multiple templates for each entity type.
To remove an entity as a template, click on the Remove as template action that replaces the Set as template action detailed above.