To study the vajrayana, or the tantric teachings, your mind has to be clear and precise. You have to be extremely disciplined. So, if you want to hear the vajrayana, a good suggestion is to go back to square one, to when you first encountered the dharma, the teachings of the Buddha. You might discover greater things in that way. Maintain your basic style of practice, as if you were a newcomer, which in a sense you are: You are a newcomer to the vajra world, the world of tantric teachings.
From The Tantric Path of Indestructible Wakefulness, Volume Three of The Profound Treasury of the Ocean of Dharma, by Chögyam Trungpa, page 61