This manual is intended for individuals who are involved with consciousness-altering substances and are interested in their optimal use. It is particularly dedicated to those who want to lead sessions with psychoactive substances or are already doing so. Additionally, individuals who wish to explore inner spaces privately and in smaller groups will find important information here. This comprehensive practical book offers insights into professional work with altered states of consciousness for all those interested in this topic. It is a revised and expanded new edition, featuring a detailed and updated chapter on particularly recommended therapeutic music.