Wim Hof teaches how to deepen his breathing exercises by using intention to engage interoception. If 30 breaths don't work, extend to 40 while lying down. State intentions like "I am going into my body" to command your internal awareness and let anxiety recede.
Chapters
If 30 breaths in the breathing exercises are not bringing you into the depth, do 40 breaths. Make sure you are at peace when you go lying on the sofa. Take your time to work yourself because most of the intranquility, the blockages, they come up and they block you from going into the depth. If you are unrestful before you start. If you use your intention: "Now I'm going into my body." "And now the world is out there." "I'm going to shut down, go inward." Then it should work a whole lot better. That is called the power of interoception. Interoception is commanding through intention your own awareness, your body awareness. And it will then shut down the world to go in. Because the interaction can cause quite some anxiety. That is hard if you don't use the intention. If you just go into your meditation of breathing practice.— and thus it will block it. You will not be able to go into the depth because the body has changed. Learn to use the intention. Before you go in: "I want to go in." "I take my time to go in." "And that's it." "And now I begin." Then you will go into the depth. Boom!