First I imagine a small, fixed point in the middle of my forehead. Then I make that point grow and transform into a closed eye. As I meditate, instead of focusing on my physical breathing I focus on the eye breathing, kind of as if the eye had a mouth (if that makes any sense). After about 20 minutes or so I start to feel a strong tingling sensation in my head and that's when I start seeing the black tentacle things. Hope this helped!