If it is a mentally stimulating game and I am paying full attention, I will just sit in silence and play. It is an intense focus but it can also be quite meditative. The best poker is always played in the full awareness of the present moment.
If I am not on my A-game, I will just stick on a podcast, some music, a TV show, or some other enjoyable poker videos. It passes the time when bored fishing and helps keep me patient as opposed to tilting. It isn't optimal, it is pretty auto-pilot, but if the table selection is good then it doesn't matter. Good things come to those who wait.