You can set properties in a sub-template from the main template easily, because they're all available as properties of the instantiated sub-template object. Here's an example:
// instantiate the sub-template Header header = this.Create<Header>(); // include the meta tag header.IncludeMeta = true;
In this case, IncludeMeta is a boolean property defined with a [Property|http://docs.codesmithtools.com/display/Generator/Declaring+a+Simple+Property] directive in the sub-template.