From: Awakening from Belief 6b
Ken: I want you to go through situations where reactions come up and feel where the reaction arises. And you'll notice that by all of the sensations that arise in your body, and emotions and things like that. If you suddenly get lost in thinking it's a very good indication you've hit reactive material because everybody uses the intellect to get away from feeling. If you go to sleep that's also a good indication you're hitting reactive material because that's a great way of checking out: "I don't have to feel anything."
Student: What if you've forgotten what you were reacting to?
Ken: Well, you've gotta go back and do it again, and the way practice works here it's exactly the same way that shamatha works. You sit down in shamatha, you breathe, get lost in a thought, after a while you go, "Oh yeah, that's right I got lost in a thought," and you come back and you breathe again, breathe, breathe, breathe, get lost in another thought, "Oh yeah." But as you do this over a period of time, you begin to move back until a time comes when you're sitting there resting with the breath, and a thought comes up and you realize, "Oh there's a thought." But you don't get lost. You're just, "Oh." And it goes up and it goes poof, and you go, "Hmm," and you're just there the whole time.
And that's actually developing a capacity of attention so you can experience a little reactive process, because a thought is a little reactive process. So we're doing this on a larger scale now. You just keep coming back, keep coming back, keep going through the same situation. You're going to get lost, confused and all kinds of uncomfortable feelings will come up, etc., etc. You keep going through it, and this way gradually you're going to hit whatever that reactive process is based on, which is some kind of uncomfortable feeling.
If you hit that--and you may or may not--just rest in that feeling, because at this point you don't know that it's a feeling. It feels like a fact to you. That's why you run away from it. That's why the reactive patterns kick up, just to get away from it.
So you need to develop your capacity of attention just to experience it, just to rest in the experience of it. That may take anywhere from five minutes to ten years, and when know--and I don't mean intellectually, I mean experientially--when you know it to be a feeling, then everything changes.
So that's the big scheme of the practice.