So many people miss the point when I speak about the importance of initial keyword research
It forms the basis for the website, in effect the start line. Nothing should ever be set in stone.
During this research we are able to diagnose what keywords are attainable and which ones are not, for example, brand new websites will naturally react poorly to popular terms.
Once a site is live, it's then a matter of adding regular good quality content and working on the sites link profile, whilst continually monitoring keyword performance.
Going forward It's normal to tweak a sites keywords, generally moving from uncompetitive phrases through to premiership phrases.
The whole process of
SEO is long winded and very systematic, I guess it suits the way I work. 10 years ago I was responsible for the Health and Safety of a very large establishment. Due to many factors people where working in unsafe conditions, of course there was not a chance in hell I could improve matters overnight, so I set up a programme of long term improvements. 3 years later the establishment was the flagship for Health and Safety in the County. Internet marketing is very similar, understand what needs done, be patient and be expected for some very late nights.