Evaluation requires you to cast a critical eye over your work. Do this after completing your template page and before writing any more pages so that you don't duplicate problems through your entire site.
Remember that your page is understandable to you because you created it but it isn't for you, it is for your users. Imagine you are a typical web user when evaluating your page. Be critical: consider how you can improve the experience of using your site.
A web site doesn't have to be 'pretty' to be useable. Focus on usability first and steer clear of 'party tricks' that you think will make your page look cool. That flashing, animated gif of a cutesy bunny won't enhance any users experience and is almost guaranteed to annoy them instead. Annoyed users don't stay long.
When you are satisfied with both the construction and design of your template page it is time to return to the construction phase to complete the rest of your web site.
Always validate your code after any change. This is particulerly important before you duplicate your template otherwise you will copy any mistakes through every page in your site.
Duplicate your template page so you can produce the other pages for your site. Validate each one when you have finished adding its content to ensure you haven't introduced any mistakes.
Your code should be easily maintainable. Appropriate use of comments and clear code layout will assist this greatly.
When you have your completed web site, evaluate it again to consider it as a whole.
The evaluation of the site as a whole should focus more on its behaviour as a unit than on the details of page layout, which you have already thoroughly considered when designing the template page.
Remember: you created your site so you understand it, but you aren't the intended audience of your site. You must consider how a first time user will cope with the experience you are providing in order for your site to be sucessful.