My ideas come from everywhere: while having a conversation, watching the news, traveling, walking our dog — see the photo below…isn’t he TOO CUTE???
Anyway, if you pay attention to the world around you (even the most mundane details), a story idea may pop up. I also find it helpful to explore other art forms — visit a museum, go to a play, listen to music. That’ll help the creative juices flow. It’s also great to have a creative buddy or critique partner who will ask tough, intelligent questions about your characters, plot, etc. A fellow artist/writer is your best bet, or at least someone with a very strong artistic sensibility (you don’t want to buddy up with someone who thinks books are dull or who finds reading your work to be a tedious chore). My husband produces and writes for the movie industry, and is actually the first reader and editor of all my writing projects. He’s very helpful with plotting/pacing because his taste is much more commercial than mine. It’s awesome to have my early drafts analyzed by someone who loves stories as much as I do. And of course, it’s great to have a dog who will think you are perfect no matter how terrible your first draft.