Here's the official Macromedia how-to on this subject:
The rest of this post is out of date....please scroll down to my latest post to see the best way to edit your templates in DreamweaverMX.
You can edit your templates using a visual editor such as Dreamweaver by inserting the following line at the top of the template file you wish to edit:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
This makes life SOOOO much easier for anyone who is used to designing with a visual editor. No, it won't render the Smarty code, but it WILL render the HTML code:
Once you add that line (make sure it's the FIRST line in your template file) you will see tables and image placeholders for page elements. It's not a perfect solution, but it helps me quite a bit when editing templates with DreamweaverMX. It appears that you can just leave that line there and it won't cause template errors on the server, but I haven't thoroughly tested this statement so do it at your own risk. If you're really worried, you can delete the line once you're done visually editing your templates.
Getting back into x-cart dev after a long hiatus. Modded lots of x-carts from version 3.1.x to 4.1.x. Developer of ImageScaler mod, Pre-login per user coupon mod, Wordpress feed mod, DigitalSubscriptions mod, Phonetic bulk download keys addon for DownloadExpander mod, Serial Number Generator for ESD products, Custom CMS/LMS integrations, external products mod, and more.