The discipline of maintaining a healthy and comfortable posture can be extended to the activities of standing, walking, and lying down.
Set aside a day, or part of a day, to spend in focusing attention and the other metal faculties upon the sensations and physiological processes of the body.
Take special care to monitor the qualities of spinal alignment, muscular tension, and breathing at frequent intervals.
As always, when distracted from your primary task by persistent thoughts or the demands of everyday life, gently return your attention to the sensations associated with structure, balance, relaxation, etc., as soon as you have noticed that the mind is wandering.
It can be instructive to keep a journal of such exercises as this so that in future you can assess their contribution to your overall understanding of contemplative practice.