Custom template and blog page

Hi

I’ve just designed a site using WP 2.8.1 and as the site is quite small I used a PHP page for most of the pages as each page looked different from the others.
I therefore used the

<?php
/*
Template Name: Name
*/
?>

So I could style the page exactly how I wanted it.

This is fine, until it comes to the blog page. I did the same for the blog, but when I create a blog post and then navigate to it, the page does not have a template(custom markup) behind it.

You can see what I mean : here.

If you click on a link for the blog post, the page opens and has no template and looks a mess.

How will can I make it so that any blog post will use a default template I create?

Thanks