Close the eyes, do not hear. Send some message to the mind that's okay to fall asleep because that's the mind thinks that closing the eyes means that it's time to go to sleep. A quiet environment is highly recommended and then smell, taste, touch, a neutral environment so that the senses are not, they don't kick into action. Our mind is mostly engaged with processing sense inputs.
Swami Sarvapriyananda teaches the Katha Upanishad, one of India's most revered texts which is also a part of the Vedas. It is a collection of philosophical poems representing a conversation between the sage Naciketas and Yama (god of death). They discuss the nature of Atman, Brahman and Moksha(liberation).