The most important element that you need to keep in mind will be keyword research. Many web designers tend to ignore keyword research as they feel it is not important. When you're building a website regardless whether is a social networking site or a personal blog, perform keyword research to identify the most appropriate keyword that will attract huge amount of traffic to your website. Check out the following post on how to perform keyword research
Secondly, your keywords need to be placed strategically on your website. If you're using WordPress, Yoast SEO plugin will guide you through. If you're building your website on different platform learn how you can implement those keywords.
Make sure your keyword appears on your URL. For example, your keyword can be "lose weight in 90 days", so you URL should be wwww . example . com / lose-weight-in-90-days. Make sure your permalink shows your keyword.
Make sure the image used for your website is copyright free and optimized for the search engine.