Self-sustaining vibrations are vibrational frequencies that have manifested and are continuing to manifest due to your attention to their manifesting. For instance, your home is a self-sustaining vibrational frequency, for you gave enough attention to its vibrational frequency that it manifested and now that it has manifested you continually give your attention to that vibrational frequency and it will thus continue to manifest in your life experience as a result.
To harness the power of self-sustaining vibrations, you should make the vibrational frequency of your dreams being a reality a self-sustaining vibration by giving your attention to the idea of your dreams, a thought that is a vibrational match to your dreams, to the extent that is necessary in order for a matching manifestation to appear in your life experience. Once a manifestation appears in your life experience, you can then give your attention to that manifestation, that experience, that is a vibrational match to your desire's manifestation in your life experience in order to continue vibrating in harmony with that vibration. This process will lead to additional experiences you can give your attention in order to continue attracting thoughts and experiences that match the vibrational frequency of your desires to ultimately make it a self-sustaining vibration.