Here is a tip I picked up in my experimentation.
The documentation leans heavily on the routes in your API config. If your controller isn't covered by a route, it won't show up. Additionally, the order of the routes in your API config is the order of the operations in your documentation.
To cover both of these points I have created named routes for each controller. This has the added benefit of making each route specific, rather than a single route with lots of optional bits. This ensures all my operations appear in the documentation, in a good order.
I have also added the API tester so the API can be called directly from the documentation.