Creating templates from a web design is a slightly different form of layout creation. There will be certain limitations specific to the application (web package) for which the template is being made.
Templates for CMS & Blogs
"Themes" is the popular word for templates in most CMS & blogs. A theme comprises of a web layout, the necessary images, icons & buttons. It will specify how a dynamic left and right columns should appear, and we can also customize the appearance of each boxes in the content.
A layout design has to be separated into convenient pieces and appropriately coded so that it will be presented as a single entity in browser. So a table-less design with semantic code of layout should not only be complete for whole page. Each part of the layout should be able to exist on their own.
CMS - Drupal
Drupal have a highly flexible templating system. For example, this very site runs in Drupal, and uses three different layouts in four themes. In each theme, the layout is coded in about seven php files along with 3 external css files and the necessary icons, buttons & images in a folder.
Blogs - WordPress
WordPress have a good workable template system. It can also be used as CMS if needed. Apart from the regular template requirements, the wordpress theme needs to be follow certain procedure so that any new plug-in can work seamlessly and without breaking the code.
Templates for Shopping carts
Templates for shopping cart packages vary widely. In some shopping carts, the layout can be split into header and footer files while some may have a sophisticated system like Smarty templates which allow customization of each & every screen of the application.
Smarty Templates
Smarty templates is an open source templating system followed by many php applications. Some others initially followed this system and added their own variations of it for their applications. So a large variety of applications uses Smarty as a basic core particularly in ecommerce applications.
Having experience with various templating system helps in creating efficient templates out of web design.
