The two main parts of a template are the content management code and the theme. These should be kept separate so that the theme can easily be changed without affecting the structure. For example, the styles should be defined in an external style sheet and not embedded in the HTML code of the pages. The structure of a website will be defined by a set of templates. It is good practise to make the templates modular rather than having page templates containing all the code for each page. This allows site-wide changes to be easily applied. For example, the footer may be mostly identical between pages.
While using web site templates a person needs to be careful about certain things. It would not be a good idea to opt for the wrong theme design. This will give one‘s site a dated look which is definitely not desirable. One should also ensure that a template is in sync with the theme and content of a site. For instance, a children site should not use a corporate theme based template. This looks quite unprofessional and mars the appeal of the site.