Vijnana Bhairava Tantra · Dharana 37 · Verse 60
Vast open place
Sit or stand where the view is wide and almost featureless: open sky, a plain, a large empty room. The lack of landmarks is the method. The mind likes objects to rest on. Give it as few as possible, and stay with the expanse until thinking has nothing left to add.
Older line
Let your gaze rest on a place without trees, mountains, walls, or the like. As the mind dissolves there, its restless movements fall away.