Your website must be appealing to your users. But it is also necessary that people will actually find your website. I will optimize your website so that it will be among the top results in search engines such as Google.
Search engine optimization is mainly about common sense. What is good for visitors is also good for search engines.
There are some ugly tricks to be ranked high among the serach engines. But using them rarely pays off. The algorithms of the search engines are constantly evolving to spot cheating. Therefore, it is important to use common sense, because it will work for users and search engines now and in the future.