Sometimes I come up with characters that resonate with me, but no plot. The characters sit around, probably sipping tea, coffee or some such, waiting for a plot to show up. When one does, I start writing.
Other times, I have a plot and no characters. There is no distinctive character voice(s) that draws me in to start writing.
At some point, I’m going to have a setting show up waiting for both a plot and characters.
Maybe, just maybe, if I have enough of this going on in my brain, they’ll get together and knock some socks off.