Well the hallucinations will vary a lot between individuals. After you enter SP, you can try to visualize a dreamscape, and enter it that way. This technique is know as a VILD (Visually Induced LD). Or you can let the dream eventually form itself. Pay attention to the hypnotic imagery, that's what will create the dream setting around you. You have to stay conscious though, otherwise you'll enter the dream non-lucid.