Study a single sutra by selecting the pada (chapter) and then the sutra (verse).
Source: How to Know God: The Yoga Aphorisms of Patanjali (Swami Prabhavananda, Christopher Isherwood)
Thus we may cultivate the power of concentration and remove the obstacles to enlightenment which cause all our sufferings.
Source: English translation of the Yoga Sutras of Patanjali (Swami Jnaneshvara Bharati)
That Yoga of action (kriya yoga) is practiced to bring about samadhi and to minimize the colored thought patterns (kleshas).