Q: I have been practicing leave the mind and emotions alone, but I often find meditation boring.
A: In order for the experience of meditation to be endlessly fascinating and infinitely compelling, you have to be interested in 'nothing'. Day in and day out, we are constantly pre-occupied with one thing or another, always busy with 'something'. But if you want to experience profound meditation, and a depth that liberates, the objective of your attention must be nothing -- absolutely nothing whatsoever. If you are attempting to meditate, but are not actually 'interested' in nothingness, then of course, you will be bored. That's just like sitting in a darkened movie theatre, waiting for a film to start. Eventually you will experience frustration and boredom.
But imagine that you are sitting in that movie and instead of waiting for that film to begin, you become interested, passionately interested, in the darkness, in the nothingness. There is 'something' in the nothingness that once discovered is infinitely compelling, and absolutely absorbing. There is an ungraspable mystery there and there is nothing boring about that mystery. Nothingness is what existed before the universe was born. How could something come from nothing? That is the greatest mystery. That's what you would be interest in, as you contemplate the darkness. The more deeply you are able to penetrate the nature of nothingness, the more the mystery of being and non-being, of life and death and that which transcends both begins to reveal itself. There is more to nothing than meets the eye.
Once you truly become interested in the darkness, you wouldn't want the movie to start. You might actually be disappointed when it started, because it would take you away from your meditation.