You will probably get more useful responses if you can give more information, or even better link to a profile, for one of the ancestors where you are 'stuck'. For example in my research I have seen innumerable Kuhn, Kuntz, and Kunst families (but not Coones) in Gelderland and South Holland.
Answering more generically, if you put the surname in the search box above the profiles it will take you to a 'genealogy page', such as this one - there is a list of 'related surnames' on the top right that might give you some ideas on a few other names to look under.