Creating high quality content takes a significant amount of at least one of the following: time, effort, expertise, and talent/skill. Content should be factually accurate, clearly written, and comprehensive. So, for example, if you describe your page as a recipe, provide a complete recipe that is easy to follow, rather than just a set of ingredients or a basic description of the dish.
Search engine optimization is a method for sustainably influences search engine rankings. Google and other search engines calculate their search results for keywords using highly complex algorithms. The individual ranking factors and their weighting within the ranking calculation are well-guarded intellectual property that belongs to the search engines and is not publicly disclosed.
Big sites can rank for the most general terms. Smaller sites within a very specific niche can do the same. Of course, it’s also easier if you’re writing in a language that is not spoken all over the world. For most smaller sites that are writing in English, however, the general rule of thumb is this: start with a big set of long tail keywords which have little traffic, but you can rank for more easily. Then, work yourself up to the rankings step-by-step. Once you’ve gained some SEO authority, start optimizing for more general keywords. And in the end, maybe you will even be able to rank for your head keywords!
One common scam is the creation of "shadow" domains that funnel users to a site by using deceptive redirects. These shadow domains often will be owned by the SEO who claims to be working on a client's behalf. However, if the relationship sours, the SEO may point the domain to a different site, or even to a competitor's domain. If that happens, the client has paid to develop a competing site owned entirely by the SEO.