twisting the core
Take the core of a product that you like/know and is successful, and twist it - enhance, change, reduce.
If that's hard, zoom out some more on the core and modify that - e.g., GitHub's core is probably pull requests, but maybe zoom it out to open-source code as the core.
Cores: Notion -> blocks Miro -> canvas ChatGPT -> chat Slack -> channels GitHub -> pull requests Jira -> tickets
Maybe these aren't the cores; it's just my opinion. Find the bit you think is the core and work from there, or improve it - there's always something to improve.