Start by slowly rolling while you focus on the end of one of your fingers throughout the roll. Change fingers from time to time and keep breathing all the time. Add another finger from your other hand to this and keep track of both of them during the rolls and yes when you are up as well. Work to do this in the most comfortable way you can and stay upright when you stand and move.
Next use a shoe lace or something like it with a tie at the end of it and focus on the tie during the roll and the standing time. Add after a while another shoe lace held in your other hand and watch them both throughout the rolls and standing time.
Last have a partner stand at various distances and angles to you and roll. after a while add him moving to to the drill and at last keep track of him moving and a non moving object as well like a car or a tree.
Remember that the benefit from this work and most of Systema work comes after the learning is done. During the work you receive a much needed humility dose and the benefits to your performance in body and mind and soul will come to you afterwords when the dinner is digested.