Gmail can be customized to a great extend. You can use labs options to add more features to Gmail inbox or use themes to change Gmail look. We have already seen Greasemonkey & userscript that allows you to render simple and minimalist look to Gmail. If you find that confusing to implement, then checkout Minimalist Gmail Firefox extension.
As seen in above ‘before’ and ”after’ screenshots, the final minimalist Gmail look is really simple and allows you to focus on email content of your Gmail inbox. This Firefox extension offer lot of options to customize the simple minimalist Gmail look. For example, you can remove footer, ads, hide header, labels, button and lot more. Grab Minimalist Gmail Firefox extension