Settle into a comfortable sitting position, either on a straight-backed chair or on a
soft surface on the floor, with your buttocks supported by cushions or a low stool.
If you use a chair, it is very helpful to sit away from the back of the chair, so that
your spine is self supporting. If you sit on the floor, it is helpful if your knees actually
touch the floor; experiment with the height of the cushions or stool until you
feel comfortably and firmly supported.