Hi,
Depending on the Odoo version you're using, the precise syntax for inheriting server-side and client-side templates in your custom modules may change. In general, though, you'll need to declare your own template in the XML file for your module using the proper tags ( for server-side or for client-side). The template you want to change or inherit can then be specified using the inherit_id attribute. The position attribute can be used to specify where your modifications should be inserted into the inherited template.

Hope it helps