Before improving your site,you need a solid keyword research.So,I always follow the below steps which are very helpful-
1.Open a .xlsx file and save it in my pc
2.Write down Niche here and also write some keywords through brainstorming.
3.Now go to Google and write the Niche here and scroll down to see suggested keywords.Pick some keywords from here too
4.Go for Keyword Shitter and find some ling tail keywords for the site.
5.Now u have a list of keywords but with no search value and CPC.So,go to Google Keyword planner.
6.Put all keywords here and click on "Get search Value"
7.Now I will get all keywords average monthly searches with suggested bid too.
8.I can also find more keywords using keyword planner tools.
9.Downtload all keywords and sort it.
10.Delete all irrelavant keywords.
10.Now I will have a fresh keyword list with search value and CPC.
Thus,I can get more valuables keywords that really boast your website
I also give Pro-Level Keyword research at higher rate