Very good advice on thoughts

Here's how to handle thoughts arising in meditation:

Whatever thoughts and emotions arise in meditation, allow them to rise and settle, like the waves in the ocean. Whatever you find yourself thinking, let that thought rise and settle, without any constraint. Don't grasp at it, feed it, or indulge it, don't cling to it, and don't try to solidify it. Neither follow thoughts nor invite them; be like the ocean looking at its own waves, or the sky gazing down on the clouds that pass across it.

-- Sogyal Rinpoche