I love doing deep meditation, but have one recurring problem with keeping up a regular practice for more then several weeks.
As I am already over fifty years of age and have a deeply ingrained habit for being high strung, I find that the noticeable, physically calming effects of a meditation session vanish after about an hour. This has already lead to frustration concerning AYP several times and a break in meditation practice until, in every case, the yearning for the bliss experience of meditation returns.
So now I have added a relaxation technique to my daily program of two deep meditation sessions - the relaxation response by Herbert Benson, which as a breathing-based technique could be counted as pranayama, I presume.