What is the best thing to do if my mindfulness practised is disturbed?

See the disturbance as a part of your practice when you notice that you are no longer focusing your mind on the present moment, on the breath or the body scan and your mind has wandered or has gone to another thought or space. Then with an attitude of gentleness and curiosity, simply bring your focus of attention back to the present moment, back to the awareness of feelings and sensations of your experience now. If the disturbance is too great maybe it is appropriate to stop your practice and resume at another time.