[jsmith99]

Whenever I build a new feature with it I end up with several plan files leftover. I ask CC to combine them all, update with what we actually ended up building and name it something sensible, then whenever I want to work on that area again it's a useful reference (including the architecture, decisions and tradeoffs, relevant files etc).

[Sammi]

Yes this is what agent "skills" are. Just guides on any topic. The key is that you have the agent write and maintain them.