Here's one way to approach a niche
I know trying to find the right niche can be super hard, I'm still refining mine. If you are like me and want your website to be about more than just making money (and no, there's nothing wrong with making money!), then this short youtube clip might help.
Adam Leipzig gave a short TEDx presentation on finding your life purpose in 5 minutes. I'm finding it really helpful in getting clarity about what I want to do.