Try meditation before bed. Visualize yourself as great tree sinking its roots deep into the ground. Also you should sleep with an amethyst under your pillow. It also wouldn't hurt to hang a dream catcher above your bed.
Haveing experience with such things it is my understanding that prophecy cannot be controlled or suppressed. That is the negitive side of the gift. Although I in my experience can say that for me meditation has increased the clarity of my visions.