It is kind of a cliché that authors and writers get frustrated by being asked where they get their ideas from. It seems that people suspect we are part of a special club, or part of a secret mailing list. I wish it was that simple, but it isn’t. Finding ideas – good ideas – is hard work.
You have to dig for good ideas. You have to feed the muse. I recently spent a day going though Victorian-era medical articles online, and discovered gold dust. Today, I went and bought a whole heap of cheap secondhand books, including some reference books. I can guarantee that every one of those books will contain at least one new, unique and unusual idea. You just have to be ready to recognise it.
And that is the skill that writers have. They learn to grab onto a inspirational idea with both hands and hang on.