Vows guide our decisions, help us prioritize how we spend our time, resources, and energy, and allow us to discern whether our actions are in harmony with our deeper aspirations - helping us live intentionally instead of letting our decisions be determined by habit energy, inertia, fear, selfishness, or a lack of imagination. I first discuss why it can be so hard to stay true to our intentions, and then I present five aspects of the Buddhist practice of vow that make it a powerful way to shape our lives.