Making the smallest changes can sometimes have the effect of snapping us out of autopilot and really appreciating the present moment. This is the second in a series of posts about mindfulness exercises that you can incorporate into your day.
On first reading, this sounds incredibly depressing, but hear me out. When someone is talking to you on the phone or you're going to meet someone, the exercise is to remind yourself that "This may be the last time I will be with this person". Notice any changes in how you speak and interact with this person.
Often when we talk to people - especially people we see very regularly - we are distracted and only half paying attention. The thought that we might not see them again, snaps us back into the present moment and helps us view the conversation in a different light.
Source: How to Train a Wild Elephant & other adventures in mindfulness