If we consider that a good design and an accessible navigation architecture depend on users staying long enough on our website to get our message across, then the first requirement is to be a good web designer.
If we consider that the speed of our web page depends on a clean and refined programming, then the second requirement is to be an excellent web programmer, since he/she must also know enough about programming to generate the meta tags of all our web site, generally automatically, since doing it manually, especially for large sites, can be very time consuming.
If we consider the effect that the words we use in our web page have on our users as well as on search engines, then the third requirement is to be a great marketer with extensive knowledge and handling of electronic advertising.
Finally and considering the amount of work we will have to do and the fact that search engine optimization is not an exact science the fourth and perhaps most important requirement is to be a hard working and very patient human being because we will have to do many, many tests and constantly rectify possible mistakes.
So if in your search for positioning your web page and you come across some know-it-all guru, stay away immediately because he is probably a charlatan.