The process for creating a new verb for activity streams is modeled largely after the microformats process.

1. Ask why: develop or extract a real-world use case. solve the simplest problems first, and avoid compounding multiple problems. Ask folks on this list whether the idea has been raised before or search around for previous work. Always attempt to invent as little as possible. 
2. Document existing behavior: this is the first step of the scientific method and it helps to ground our work to what's actually being done. Collect as many examples as you can find, ideally from more than one unique source. Read more: http://microformats.org/wiki/why-examples
3. Create the appropriate pages on the wiki:
   • verbname examples
   • verbname formats
   • verbname brainstorming 
4. Iterate.