In writing this blog, I can only go by my own personal experiences. So with that being said, this is how the transition of power worked for me.
During the "getting to know each other" phase, as the as the communication and understanding are working, trust is being built. As the submissive begins to let her guard down, she is opting to release a certain amount of control.
That control that the sub releases is for me to take over. So eventually over the course of months she will eventually give me complete control of her.
But don't get it twisted, because if I say or do anything that I haven't cleared with her beforehand, the transfer of power stops. Unless it has been discussed beforehand, you are not to immediately assume control of the submissive. As this can actually backfire. However, doing it the way I outlined makes for good, steady and consistent transfer of power.
Hope this helps,