Start first with some deep yoga breaths, feeling the body being breathed by the air moving in and out of the lungs. Feel the body settle, the muscles releasing from their effort. As the body settles into just the movement of breath let the mind start to settle as well.
Begin to see your mind as if it were a quiet, deep, still mountain lake. No other person around and nothing but the sound of the wind in the treetops. The lake is a beautiful blue and crystal clear. You can see through the water to the sandy bottom.
When a thought begins to arise in the mind, see it as a bubble rising from the sandy bottom, moving to the surface through the blue water. As it pops at the surface the ripples move outward towards the shoreline. The ripples grow further & further apart until at last they subside and the lake is still once more.
Each time a thought arises just see it as another bubble surfacing on the lake. Do not give into judging the appearance of the bubbles of thoughts arising, no matter how many nor how few. Just let them arise, watch the ripples of them move towards the quiet shore, then see the lake-mind settling into stillness again.