You have learned restraint and principle, easy posture and control of your breathing (out).
Now its time for pratyaahaara – prati aahaara – against ‘food’ for the senses.
ie its time to turn your mind away from what the senses proffer upto it.
You can practice prANAyAma with Shanmukhi Mudra.
You can close your eyes, ears and mouth. You need your nose to breathe and will have to touch at least the clothes you are wearing or the seat you are sitting on.
Also, in these days of loudspeaker religion and politics, tvs and constructions, how many sounds can you block and for how long?
So the important thing is to be able to stop paying attention to the data-stream that your senses are continually relaying to you.
You may pay attention to your breath, since you are doing prANAyAma.
TV absorbs your eyes and ears and mind. Books absorb your eyes and mind.
When you close your eyes and sit quietly in a silent place, having given up fun times with friends and duty times of work, you mind has a free reign and starts thinking away about what has happened upto now and what needs to be done next.
It thinks of beautiful places, people, sounds and food. It rakes up the past and wants to negotiate the present.
You have to let the thoughts go by without chasing, building and expanding on them. Observe the activities of your mind and turn away from them, don’t follow-up on them.