Which are the best output words?
In general, they are the most used in your website or blog and those that lead users to related topics (close to the topics treated in your blog).
For your best, remember that they must be topics that your users could be interested in. Otherwise you will not obtain credits.
Namely if you have a blog who talks about "restaurants", try to choose output words related to the "tourism" or the "leisure time", for example. But do not make an effort adding words related to the "automotion" since probably, you will not use very much often these terms in your blog and your users will not be very interested in these topics.
Always think about the user!
Thanks for your time