The simplest way to supplement the practice is establishing a reminder that prompts conscious awakening and subsequent indirect techniques. This may be accomplished by blindfolding the eyes or tying a cord taut around an arm or leg. The idea is that the reminder is immediately felt when the practitioner wakes, prompting the attempt of indirect techniques. In actuality, mind-machines work using the same principle since these are most effective as cues that arouse an intention to perform a specific action.
A more sophisticated example of a reminder is when a practitioner dozes off in a position meant to cause numbness to a certain body part. While awakening, the practitioner will take the physical numbness as a cue to practice indirect techniques. A secondary benefit to this method of physiological signaling is that the numb body part may easily be used to perform phantom wiggling. Falling asleep while lying on the back with an arm behind the head, or by lying directly on an arm are effective examples. These and other postures will impede circulation, cause numbness, and promote awakening. Naturally, the numbness should not be excessive.
Diverse experiments that exploit physiological needs are especially popular for inducing conscious awakening or becoming conscious while dreaming. For example, a practitioner may forgo water over the course of the day before attempting to enter lucid dreaming. The effect is an acute thirst while dreaming, which may be used to communicate that the dream state has taken over. Or, thirst causes repeated awakenings, during which the practice of indirect techniques may commence. An alternative to depriving the body of water is including more salt in foods consumed before going to sleep.
Another method is to drink a lot of water before sleep, causing the practitioner to awaken, naturally producing an opportunity to perform indirect techniques. Using this has been known to result in dream consciousness.
Another popular method helps with direct techniques. It works by falling asleep while keeping the forearm propped up at the elbow. When the practitioner falls asleep, the forearm falls to the bed as the body shuts down. Feeling the arm fall signals a lapse of consciousness, after which direct techniques may be attempted. If this method fails to produce results on the first try, it may be repeated by raising the forearm before falling asleep again. This method helps some, but rarely on the first try. It should not be counted on as panacea.
Like all other non-autonomous methods, practicing lucid dreaming entrance using physiological signals should not be done on a regular basis. There are more pleasant, autonomous techniques that only require natural willpower and healthy desire.