|Aranya's Yoga Philosophy of Patanjali my personal favourite presentation of the Yoga Sutras partly because he had lived in a cave for twenty odd years before writing it and had also studied western philosophy as well as that of his own culture.|
The form practice takes may change, practice Ashtanga Vinyasa, switch to Iyengar for a few months come back to Ashtanga, Vinyasa Krama, hell, try Bikram or go to the gym class if that's the only one available.... or practice something, whatever it is, at home.
Do a fixed series or be more flexible, a couple of Sun salutations or never do another sun salutation in your life, do headstands instead or just sit and breathe, practice pranayama ( a straight forward nadi shodhana, with or without mantra, is sufficient).... or not.
Or sacrifice mat time altogether in favour of bringing the mind back to the breath throughout the day, to the yamaniyamas, an object of devotion...
A regular form of practice at a regular time can be a useful tool for developing discipline but a tool nonetheless and probably of little value if it doesn't begin, after a time, to permeate our whole day.
What constitutes the practice Patanjali is referring to ?
Practice = The repeated, enthusiastic, attempt for attaining the undisturbed calmness of mind