Help finding “Breath Energy” as described by Thanissaro Bhikku

I plan on calling the Metta forest monastery with this question shortly but have not had the opportunity yet to do so. In “With Each and every breath” and in many of Thanissaro’s guided meditations he talks about playing with the “breath energies” of the body in meditation. While I believe I have on occasion felt these sensations in my hands, I have struggled to feel them elsewhere in the body, particularly their movement from the base of the skull down the spine as he often stresses is the most important place to feel these energies. If anybody as any experience with this particular form of meditation and tips on sensitizing myself to the breath energy of the body I would be keen to hear. Thank you!