Metta or Loving Kindness
"It takes boldness, even audacity, to step out of our habitual patterns and experiment with a quality like kindness - to work with it and see just how it might shift and open up our lives."
"Love is not a feeling, it's an ability"
Sharon Salzberg
Perhaps as we practice over the years these qualities emerge naturally by themselves, but it also seems a good idea to try to cultivate them, give them a nudge, so to speak. Like in meditation we gently return our mind to here and now instead of ruminating on the past and future - in metta practice we gather some of the energy wasted on habitual reactions and use it in a more wholesome way. This is generally accomplished by repeating certain phrases like:
May I live in safety
May I have mental happiness
May I have physical happiness
May I live with ease