Here’s a 13 minute guided compassion meditation, also called metta. You can do it sitting or lying down or even riding the train.
Compassion practice serves two purposes. The first is that practicing compassion makes loving ourselves and others the natural inclination of our mind. The second is that cultivating compassion allows us to go deeper into our mindfulness practice, and to hold space for whatever arises. The more compassion we can hold for ourselves and others, the more present we can be for our lives.