You’ve got to harvest your inspirations when you can. I used the Inspiration app (the name suits the app perfectly) to develop the cluster, because you can just keep going. It’s got an endless canvas, so your diagrams can be as large as you like.
I’ve used Inspiration for years, going way back to the time I was a Windows person. I made the switch to Macs in 2005, so I’ve been using it for well over a decade. Wonderful app. It’s got an iPad version, but I haven’t tried that yet.
Consequently, with all the brainstorming, I managed just 300 words of the novella.