One of the first things we think of when considering a new website is how it will look. While this is an important point to keep in mind, it is far from being the most important from a marketing and SEO standpoint. Obviously, an attractive site is necessary as it is almost always the first thing prospective clients will notice. But it's what's behind that pretty face that makes a real difference.
While you're deciding on your colors and fonts, be sure you to put how you plan to use your website in your marketing strategy at the top of the list too. You want to be sure to build your site around SEO and SEM strategy, not in vice versa. You can build your site in reverse and make the marketing end secondary, but my experience this makes optimization much more time consuming.
When in the planning stages, be sure that either you or the professional you hired does keyword research and there is a plan in place on how to utilize these keywords effectively. Google and the other search engines don't care what your website "looks" like. because they don't actually "see" them. What the crawlers look for is relevancy to the search query through keywords and content as well as accounting for readability.
Trying to account for these points after the fact can be a bit tedious and very time-consuming. Hummingbird is quite keen on keyword stuffing. It actually isn't even about stuffing, but more about are keywords being used in relevant sentences. In other words being able to go back and randomly add keywords after the fact is not really an option anymore. Your best bet is to have your written content that has been completed based on keyword research ready to go.
Another at least as important aspect as looks that wins big points with both search engines and users is functionality. Google seeks out broken links on your site and can punish harshly for them. Competing in the world of SEO can be challenging enough, you'll want keep the strikes against you to a minimum. This is also a quick way to drive users off quickly.
Keeping the back end of your website in order is equally as important as the front end. While considering your design one must also consider how the back end is going to piece together as well. Keeping this in mind will save you a great deal of time, help with the SEO as well as user experience.