What is the proper way to style pages in a new installation of a drupal theme? I'm currently working on a new theme for a new drupal site, and have created a new subtheme of the adaptivetheme and am looking to modify  it to match the two psd's I've been given (one for the main page, another for the content found in trhe rest of the site. Originally I was going to copy page.tpl.php over to the subtheme from the at_core/templates directory and modify it's structure, but am wondering if that's considered best proactices drupal wise, ior if i should use modules like panel and views to build the style that I want that way?

So in a nutshell, which is the proper drupal way to style a new site; to use panel/views to match the design that you want, or to modify the tpl files, or a combination of both, or possibly something else that I might have missed?
Both or either are just fine, it really depends on what you want to achieve.

Panels will give you a UI in which you can move sections of the page around, but you will still need template files for the layouts if you don't want to use the standard ones.

Rearranging a template file is fine, but much less extendable via the UI.

In short, it's a matter of choice.  I recommend trying both and seeing which fits your needs best.

Also, check out Omega 4.x, it's a beast of a theme with some extra layouts built in and a pre-built gemfile so that you can use SASS if you want.