If your imagination runs away with you, use it rather than fight it. Guided imagery gives a vivid mind somewhere to go.

What the research says

A randomised experiment comparing mindful breathing, progressive muscle relaxation and loving kindness practice found they did not all do the same thing, with mindful breathing producing the most decentering. Different practices work along different routes, so a poor fit with one says little about the next. That study did not test guided imagery, so read this as a reason to keep sampling rather than as evidence for the technique itself.

Strength of evidence: long taught, never tested. Widely used and long taught. No trial has established that it works.