1. First Principles of Professional Esthetics

Before memorizing any facts, it helps to understand why the exam exists at all. Every question on the PSI Esthetician Theory test ultimately asks the same underlying question: will this action protect the client and the public? When you get confused on a test question, return to that frame. The right answer is almost always the one that most clearly protects health and safety.

This phase gives you the mental architecture that makes everything else in this guide easier to understand.