Selected answers from the Dumb SEO Questions G+ community.
Alan Bleiweiss: Have you tried using AnswerThePublic? It`s an amazing site. Type in a question or topic you think relevant, and submit it. That site will come up with a range of related questions, broken out in lists and alternately, visually stunning visuals. https://answerthepublic.com/
Alan Bleiweiss: Note even that site isn`t perfect - depends a lot on your starting phrase or question. However it`s a great resource to at least get going.
Neil Cheesman: You can use the auto-suggest on Google - start typing a sentence and then add a space and add a, b, c, d, etc... also - the related searches at the bottom of SERPS...
George G.: I use answerthepublic and quora. (in quora search for kwyword and a lot of questions pop out)
Neil Cheesman: I would probably add that if you are looking for an `easy option` then many will most likely have walked that exact same path and competition may be tough - so, looking `outside of the box` maybe a good option :)