When having SEO done on your site, you’ll need to get into the mindset of who’s viewing your website, why are they searching for you? what is the information they’re looking for? how will they put that into a search engine?
Before optimising a site the client will be required to choose keywords, these are what people will use to find your website, and therefore what the pages will be optimised around.
The best way to keep search engines interested in your website is to keep adding new content, this can be hard to do for certain types of companies, for example if your products or services never change then there’s not much you can keep adding to your website, this is where a blog comes into use. If you use a blog like an online diary of anything interesting that happens to be related to your company, then you can add an article to your website, this way your company website begins to fill up with work related content, more people will find your site through search engines and search engines will be more interested.