Put a thick blanket or mat down on the floor in quiet place where you won’t be disturbed.
Your pelvis needs to be off the floor so you can get both knees down on the floor, and form a stable triangle of the legs and buttocks.
Place a thick cushion (zafu), or firm folded blanket, on the mat so you can sit on it facing the wall. Sit on the front half so the pelvis is tucked out slightly; find and feel the two points of bone known as "sitting bones". If you are on them without straining, you are likely to be in balance. Then fold your legs so that you can place the left foot on the right thigh or vice versa, or simply put one leg in front of the other with knees on the floor.
Allow the upper body to rise, find its centre; sway a little left and right, forward and back until you feel yourself to be in equilibrium. Let gravity help you, don't strain against it, and notice if you lean to left, right, back or forward.
Place left hand on right hand, palms up, with thumbs touching, in your lap, so you form an oval with the thumbs touching horizontally at the top, and the fingers overlapping, not interlaced.
Let your head be balanced on your neck- not forward back or to either side; let your eyes open naturally; there’s no need to open your eyes unusually wide or to close your eyes. Keep your eyes looking at about 45 degrees without tilting your head.
Tuck in the chin, gently extend the spine as if suspended by a thread from the ceiling and let the head balance effortlessly on the shoulders.
Set ears, shoulders and pelvis in the same vertical plane, with the spine naturally curved.
Let your tongue tip lightly touch the roof of your mouth, breathe naturally and settle into your abdomen.
Finally, keep on letting go of any thoughts that come and go. Don’t follow them, don’t push them away. Relax the grip of your mind. Let all those thoughts go to the background... don't follow trains of thought. You are not trying to stop thinking, but letting be.
Allow thoughts to arise and pass and just stay present in the posture. If you get distracted, return to the posture and this moment.