Final answer:
Shamans use techniques such as trance dancing, hallucinogenic substances, and rhythmic music to achieve a trance state.
Step-by-step explanation:
Shamans use various techniques to achieve a trance state. One common technique is trance dancing, which involves elaborate drumming and masked impersonation, and is practiced in African, Native American, and Asian cultures. Another technique is the use of hallucinogenic substances such as drugs or plants, which can alter consciousness and facilitate connection to the spiritual realm. Additionally, rhythmic music, exhaustion through dance, and other means can induce an altered state of consciousness, allowing shamans to communicate with supernatural forces.