The meditations that I have found the most useful to me personally would be the visualization practice, and the loving- kindness meditation. The Loving - Kindness meditation is my favorite because I am projecting love and kindness outward into the world. This in particular helps me  to abandon judgments and anger towards certain people and their personalities. I feel so empowered by simply directing my energies and prayers to empower others.
 The visualization helps me when I am feeling off and need to feel somewhat centered. I am able to do both of these meditations whenever, wherever I am.