In this pages you will find my steps to optimise this server and site to get the higher possible rank in sites analysers. To start with already good canva I choosed to use twitter bootstrap pages.
SEO is your site indexation overview, your title and description. Some not to difficult advises.
Content is, at my point of view, the most important part of SEO. What text is in your site, does it correspond to your description, how much is it coherent ?
As design we don't talk about how your site look and feel, but how does he respect the search engines advises about security, technical description.
This is the more technical part of SEO optimisartion, you will have to get in deep on your server configuration
For the moment I will focus on nginx server configuration nut in a while I will also work on apache tuning.
Rather than accessibility I would prefer say social networking and mobile look.