vB3 - Custom templates

[Toneboy]

First post here - hope this is the right forum for this (and yes, I've done a search on the topic and not found the answer I was looking for).

Basically I've added my own site_navbar template into one of my styles (which I'm refining at the moment - I want to make sure it is right before launching it). I thought it was just case of adding $site_navbar into the template I wanted it to be shown in - could I have been more wrong?

Anyway, does anyone know what you need to tinker with to get a custom template to work?

Thanks in advance.