Google Trends:

Though there’s many niche research tool available free and paid. But one that you shouldn’t over look is the good old GOOGLE (google.com/trends) so what is this google.com/trends?
This is a section of Google where you can find of all the top and current search term on Google. This tool is so easy and straight forward that I am only to briefly skim through. As an example go to your google.com/trends now and somewhere at the bottom right of the page click on “More Hot Searches” this will take you to the top 20 hot search trends in Google at that moment (the result is life).
Please note the majority of the search terms are useless to you, but on the occasion pending on your niche or interest to your surprise a gem or 2 will pop up.
Look for hot topic (like “prvcy jeans”) or current events (like rent the runway) then just cross check the pick with Clickbank to see if products are available as a niche. As I say Google.com/trends don’t spend to much time on it but sometime it’s a good way to stumble onto your gem.