Yajña is a performance to create a strong link between the individual in physical life and an aspect of the individual in the celestial realm for the purpose of living in greater accord with the Universe. Yajñas are highly scientific and precise multi-dimensional esoteric techniques to invoke and direct the transcendental cosmic energy into concrete, tangible and constructive fruits. In Brahman Consciousness, one lives in perfect harmony with the Universe. Every individual that is in physical form is attached to a package of karma that defines the life experience. When this package of karma is balanced, then one can live in perfect harmony with the Universe.
“Ayam Yajño Vishwasya Bhuvanasya nabhihi” (Atharva Veda 9/15/14). It means Yajñas are the central focus of the Universe. When Lord Brahma created the Universe, He created Yajña to fulfill material and spiritual needs.
Almost every act from ego volition results in unbalanced karma. Unbalanced karma is a potential for reaction or a seed for action, waiting for the opportune moment to express itself and thereby become balanced. Unbalanced karma accumulates from life to life with only a small part getting balanced in a particular life and usually more new unbalanced karma is generated in every life until there are "mountain ranges" of unbalanced karma associated with most individuals. At the moment of birth, the arrangement of the planets and constellations produce a snapshot of the karma that is scheduled for balancing in the life. This snapshot of unbalanced karma may be viewed in a Jyotish chart.
There are 12 Graha Yajñas for the MahaYajña Vitara. Start with Surya and proceed doing one yajña at a time. Record each yajña before starting on the next one.