You can provide search engines relevant or core information about your website. This is really important nowadays when Google is working extra hard to understand what are our pages all about. Try writing about the latest news, create viral infographics, write top lists posts, build your email list.
Well there are many options. As to increase visitors or in other words your site's traffic, you should mainly work on SEO and increase your page rank first or a good advertising would make your site more visible as well.
As for ranking - SEO will work as well, but if you are talking about ranking that would help increasing the trust of your site - you might use some softwares and start generating opinions of your visitors. For exmaple, it could be Shopper Approved - a customer review software.
You could a video in your homepage. This brings in a clear understanding of your product/services and also helps viewers to be engaged to your website more. This is also sharable in social medias thereby giving in more exposure.