For a website to receive traffic you must have two well-developed things, web design and a search engine optimized site. Although, in the past these two were more like oil and water, and not very good at getting along, this is not the case in today's competitive world or search engine results. You must have both a well-designed site and one that has been optimized for the search engine in order to get the quality traffic that you want.
Having a search engine friendly website is a good starting point to successfully getting traffic to your website. You can do this by using online tools that are available, these tools, known as HTML and CSS valuators will "look" at your site and determine if the search engines will like what they see. If you use a web design, where the code is not well written you are hindering your chances that search engines will visit your site.
Valuators look for programming tags that are not properly used, or otherwise invalid, they also look at the layout and web design, as the search engines will see it to determine if what is being "read" is valid for search engines. Incorrectly formatted code and design flaws will be detected allowing you to modify and correct as needed, this is very important to search engine optimization, search engines must to able to "read" the site properly to rank you in results pages.
There are also commercially available programs that allow designers to active monitor and correct invalid code as the site is built, this allows for more efficient time management, as searching through thousands of lines of code to debug invalid code can be very time consuming.
While most valuators on the internet are very good, and efficient at inspecting website, the best part is that they are available free. Use them to your advantage when working on the web design and search engine optimization of your website.