In the initial section on shamatha, the Vajra Essence has the practitioner take the mind as the path, using the specific approach of taking appearances and awareness as the path, also known as settling the mind in its natural state. In brief, this consists of observing all arising mental phenomena without grasping on to them. Your thoughts, emotions, images, and so forth are observed closely with mindfulness, but you do not encourage, discourage, or involve yourself in any way with the arising mental phenomena. The aim at this stage is to settle the mind in the substrate consciousness (alayavijñana)—the ground of the ordinary mind. The text also comments on the many meditation experiences (nyam) that may be encountered and how to behave when they appear. Pitfalls are described, along with some of the deeper possibilities of this phase of practice.
If you wish to take shamatha all the way to its ground, however, it requires a supportive, serene environment, good diet, proper exercise, and very few preoccupations. The necessary internal conditions are minimal desires, few activities and concerns, contentment, pure ethical discipline, and freedom from obsessive, compulsive thinking. It is my feeling that the achievement of shamatha is so rare today because those circumstances are so rare. It is difficult to find a conducive environment in which to practice at length and without interference—even more so to have that and access to suitable spiritual friends for support and guidance. Therefore, if the causes are difficult to bring together, the result—shamatha—is also necessarily rare.