So here's an easy way to get those idea juices flowing.
type: site:www.warriorforum.com +"how do" +"?"
into Google and you will be a bunch of questions.
Obviously you can change the forum url to whatever niche you are interested in, and obviously you can change whats in the " " to, what, where and when.
If you find more then one person asking the same question, you may be onto something. A way to find that out is to choose another keyword in the question and add it into the url (+"scammers" for example).
Now you may be saying, "But Taniwha, that's too simple".
Well yes, yes it is.