Eckhart Tolle describes how ordinary consciousness always clings to thoughts, feelings, or perceptions. He offers a practice: shift your attention from mental noise to the silence and space around you. When you do, consciousness becomes aware of itself rather than of objects.
Chapters
So normally your consciousness is content, you're always conscious of something, that's normal. You're not only conscious of something, a thought, a sense perception, a feeling, a memory which is a thought, you're not only always conscious of something, you are identified with that thing that you are conscious of. Every thought that you are conscious of, you are identified with it. But you're never conscious of nothing because you think that doesn't make sense. And now we're introducing this little practice where you pay attention to the vastness of space, or you pay attention to stillness or silence around you, not the noise. You pay attention to the silence. So when you pay attention to that, You become aware now, conscious not of something, because there's nothing there in the silence or in the space. And when there's consciousness and the object is withdrawn, all that remains is consciousness that is conscious of itself.