Design doesn't matter

When looking for things to change/test on your website, design doesn't matter.  This isn't to say that design doesn't impact the performance of your site, but that design isn't the heart of your problems.

Design is a form of art.  For any work of art there are three basic components: Subject, Form, and Content. For a website, the subject is generally your company or product, the form is structure or organization of the website, and the content is what (hopefully) people see and read.  

In order to be "appealing" a well designed website strikes a balance with the seven principles of organization: Harmony, Variety, Balance, Proportion, Dominance, Movement, and Economy.  Each one of these organization principles works together to make the design of the website more attractive.  But a good design, as defined in terms of art and appeal, doesn't mean a good website.

When you shrink your column widths, it isn't that the design of your site was terrible, it is because the original layout wasn't reader friendly.  When you change the design and style of a call to action widget, it isn't that the original design didn't work with the site, it is because the original design gets lost and doesn't stand out.

An aesthetically pleasing design is very important, but the keys to increasing your conversion rates are clarity, ease of use, and function.  The message, objective, and next steps need to be clearly defined, the site has to be easy to use and navigate, and it has to work.  

If you are thinking about testing a new design, try to determine the underlying problem that a design change will fix.  If you can't identify the problem or there isn't one, your new design won't likely do any better than the original.