If you have something that you are passionate about doing then you will already know what to post about... the problem comes when you have to pretend about a topic only to post it "because you want to make money" when it should be otherwise...
If you are passionate about something, you do it because you like it and how you like it, you will have a lot of content to share, and people will notice that passion!
I couldn't agree more. Usually those who want to look smart and pretend to be smart get into trouble fast.