One way to find plot ideas is to look for precursors of them, for wisps of ideas. These are items that you find interesting in some way. If you find them interesting, a reader may as well. You are looking for items that intrigue or interest you, that provoke you, that upset you or that you can’t stop thinking about.
You can find wisps of ideas in many places. Be alert when you read news or current stories. Try browsing news archives or summaries online. Think about past events in your life and review family, romance, friend or colleague events. Consider bits from pieces others have told you in conversations or that you have overheard. Be open to wisps from song lyrics, movies, television series and books. Look carefully at your daydreams.
It is crucial to make a list of the wisps you find. List all wisps, even those you do not consider that good; expanded or combined with another wisp, a wisp may be better than you think. You never know when something on your list will blossom or be helpful. A professional photographer takes hundreds of photos of a scene and selects only a few images. That is what you are doing here, turning off your internal editor for now and just collecting wisps.
If you find a wisp online, be sure to save the link; you may want to return to it for details. I can’t count the times I’ve wished I had saved a link I found that I though was unimportant. Also, if you think the page might disappear in the future, copy the text into a word-processing document or print it to a PDF and save it.
It depends, but you probably want to collect in the vicinity of 100 wisps. Remember our photographer.