I don’t think that you “have to” do anything for the technique to work for you.
But for me what I do is visualize the dream that i just awoke form until I get to the dream sign that I chose, see myself recognizing it, doing something, and then I repeat from the beginning.
But I do know that people on this forum just say a mantra or just use the visualisation, so I guess use whatever works for you.
ypm.