This is an example of creating a template file to custom theme the Edit Account page in Drupal (user/#/edit). For the sake of an example of what "could" be done, the template is split into a two column layout, with parts of the form in each column.

This section outlines how to theme forms (CCK, user, etc) throughout Drupal 6.
Since http://drupal.org/node/101092 is quite out of date, and to my knowledge there are no comparable guides, I'm working on creating up to date guides on theming various forms in Drupal. Since it's the one I'm working on for myself right now, the first I will do is the My Account form (user/#/edit).

A short guide with references and examples of methods for custom theming CCK input forms.