No secret sauce
Google do not want your Google marketing consultant to
bamboozle you with "secret magic". That's the domain of the old
advertising companies, and Google won't play that game. Google wants
your advertising to work for you.
So, they have provided, FREE, access to a powerful tool,
which you can use to ensure that your investment is directed at the most
It's called the AdWords Keyword Tool.
Now if you're already an AdWords user, you have access to
the full (fancier) version, but there is a public version too, that does not
require you to be logged in to a Google account.
You can find it here: https://adwords.google.com/select/KeywordToolExternal
If you open the above link in a New Tab / Window, then you
can switch back and forth to follow the instructions below, while you use the