Or the Trope Launch Pad.
This is a common question asked by anyone who has seen something they know to be a trope, but they don't quite have a name or description for it, and they would like to remedy that.
Which is where the Trope Workshop comes in.
On this page, you can create a draft trope page you'd like to create, work on, and refine until you think it's ready, then transfer it to the main namespace, where, hopefully, it will be blessed by Wiki Magic and prosper.
For guidelines on how to use this namespace see Trope Workshop Guidelines