Knowing where to start is a matter of self-discovery: observe yourself. Make an inventory of what you have within, and by following the voice of intuition, you will learn to prioritize what must be worked upon first in accordance with your needs and disposition. It really depends on what you can readily perceive through daily self-observation and remembrance of the Being. God is the one who helps show the disciple the appropriate order of the work, which comes about by working on those aggregates one can directly and immediately perceive.

Study The Great Rebellion by Samael Aun Weor, specifically the referenced chapter below on this subject matter. By developing work memory in the consciousness, one is astonished to recognize a residual pattern within this matter of the dissolution of psychic aggregates. Recognizing such a fact produces genuine faith, since we realize we are never alone in this work, ever.