Raja Yoga is dedicated to all the internal aspects of Yoga.
It is known as, The Royal Yoga, because it is the highest form of practice.
The heart of Raja Yoga is the art of attaining yoga, A state when the individual has removed any feeling of separation, and maintaining the awareness of yoga.
There are many meditation techniques in Raja yoga. The first is to simply learn to remove thought from your mind and when they re-occur to remove them once again thus dwelling in a pure state of consciousness.
Techniques of Raja Yoga
Self Illumination Expansion of Light
When blending the techniques together there are a number of paths to take. Example: Start with postures that open the hips, groin and lower back then enter some breathing techniques that lengthen the breath and calm the nerves. Slowly move into meditation, after some time when the body aces move into some postures that open the areas that have pain, move into some breathing techniques then perform yoga postures again choosing ones that do not require too much energy, then re-enter meditation. Continue to perform asana and pranayama to aid in the practice of meditation.
Other techniques in Hatha yoga can be integrated into blends of practice with asana (yoga posture), pranayama (yoga breathing) and meditation. This can prolong the duration of meditation and make it much more enjoyable. "Aches and pains may aggravate concentration and cause strong distractions during meditation. In-stable breathing causes fluctuations that stir the mind. Work to bring harmony to the body and breath before moving into meditation. When harmony is lost move back into the techniques that remove the distractions then re-enter meditation."
Yoga asana seemed to manifest from Raja Yoga since they appeared some time later. The first yoga postures to be explored were seated postures. Perhaps small aches and pains in the body were too distracting and yoga practitioners naturally stretched out. Being in a higher state of consciousness the asana (yoga postures) became a sacred art of body manipulation and spiritual worship. Slowly their ability to unblock energy, aid in maintaining proper seated posture and purify the body became apparent.