To merge the properties of a sub-template with a master template, include the MergeProperties="True" attribute in the Register directive for the sub-template. When you do this, the properties of the sub-template will be displayed on the property sheet of the main template when the main template is open in CodeSmith Explorer. This makes it easy to prompt for all the properties that are required for the entire code-generation process on a single property sheet.
<%@ Register Name="SubTemplate" Template="SubTemplate.cst" MergeProperties="True" %>