When I was writing my book, Operation Mermaid: The Project Kraken Incident, I had some trouble with an idea for the plot. This happens a lot to writers. I had the main idea of some big thing transforming women around the world into mermaids. I was trying to get away from the whole plotline of being a mermaid is a secret, which is what most mermaid books are. I wanted to make it a big enough event so that it wouldn't be a secret anymore. I even brought in agents from Homeland Security. But now what? I tried to figure out a way to make a story out of this, but everything I tried turned out boring. I didn't want my readers falling asleep halfway through the novel. I just couldn't think of anything. I also couldn't explain why Homeland Security was there. I put it aside for a bit.
About that time, I remembered another idea I had for another possible book. This was about a mechanical Kraken. The mythical Kraken was a giant octopus that would come up and crush ships, taking them and their crews to the bottom of the ocean, where they would die. The new version would be a mechanical version, based on a submarine. The new Kraken would use mechanical arms for destruction. If you want more details, read my book. I didn't have a story for this, though. I had this thing, but it was just sitting there with no story.
Then, as I was working on my mermaid story, I decided what it needed was something to tie everything together. That's when I decided that the mechanical Kraken would be perfect for this. It was a submarine, so it would make sense for mermaids to be involved. It was a potential weapon, so Homeland Security would have a reason to be there. It would take some time to process, so it could drive the plot forward. To me, that was it. I put the two together. (It almost sounds like the Brady Bunch.) That got me over my block, and helped me produce the novel. I just filled in the details.
Sometimes it works that way in life, too. You have an idea for something. Someone else has an idea for something else. Neither one of you are getting anywhere. It might be time to talk about combining your ideas into one. There might be cost efficiencies in eliminating duplication. You also could get more income from your combined idea than you could from one alone. It's worth discussing.
This doesn't always work. There are all kinds of products that try to do two things that wind up in the late-night TV graveyard. There are also mergers that don't work, and legal restrictions on other mergers. But you will never know unless you try it. There are a lot of legal and other details I won't go into here. At least be open to the idea.