When I find out I'll tell you!
I new reached a stage that even thought pronunciation is super easy, my speech ability is still very weak. But I do I feel it improves a bit everyday, even without virtually no effort. So I just keep doing what I always did.
When I'm closed in my mind I can speak what I want, but when I face a real opportunity I simply can't maintain the pace. I can't come up with words at the required speed. Like an iceberg, the words are there, but very little shows up on the surface. I'm afraid of doing mistakes or I feel ashamed of what I might say.
I feel what I need now is not really output training, it is social interaction.