Before beginning Psychic Work, and between readings, I often use a meditation from Laurie Cabot's book, "Power of the Witch." The "Crystal Countdown" can be found on page 183-187. Basically, you close your eyes and visualize a red 7. Hold that vision, then release it. Visualize an orange 6, hold and release, next a yellow 5, followed by a green 4, a blue 3, an indigo 2, and finally a violet 1. This places one in the Alpha state, the state of consciousness prerequisite for Magic or Psychic Work.
Namaste and Blessed Be!