When you walk, you can do a more relaxed focus. Instead of noticing the feet, which is much more focused, aim for the lower half of the body. So, your awareness is on the lower half of the body; you’ll know a lot more things going on in the lower half of the body – sensations, footsteps, and so on.
A lady yogi, in the beginning, was so used to the old way of practicing – she couldn’t stop walking unnaturally, like doing one step and then one step. Even when she went walking in the village, she would walk in this stilted way. I told her to watch both feet at a time, not one foot at a time. Then, she started walking normally.
Initially you can watch the lower half of your body, and as you carry on, you’ll start to notice the upper half of your body; you start knowing everything. Then, you’ll start noticing hearing and seeing, thinking and feeling as well.