Their practice is, when confronted with a tendency to break or neglect the promises, reminding ourself why we made these promises and working through the delusions and negative karma that prevent us from keeping them.
Their primary function is to maintain the uninterrupted continuum of our spiritual path until we attain the final goal. The level of the promise – from refuge, to pratimoksha, to bodhisattva, to our tantric vows – determines the speed with which we complete the path, like water moving through an increasingly narrow hose. Their secondary function is to help us overcome all gross distractions, which is the basic foundation of training in concentration. This in turn enables us to successfully meditate on the Dharma and in particular on the wisdom realizing emptiness that purifies our mind of all delusions and their imprints, thus taking us to the cities of liberation and enlightenment.
Our refuge promises are essentially to (1) to make effort to receive Buddha’s blessings, (2) to make effort to put the Dharma into practice, and (3) to make effort to turn to the Sangha for help. Our pratimoksha promise is essentially to refrain from harming living beings, both ourself and others. Our bodhisattva promise essentially is to not stop until we become a Buddha, in particular through the practice of the six perfections. Our tantric promise is essentially to maintain pure view of ourself, others, our environment, and our activities out of compassion for all living beings. More details can be found in Joyful Path, the Bodhisattva Vow, Universal Compassion, and Tantric Grounds and Paths.
Our most important vow is our heart commitment to Dorje Shugden. This maintains the uninterrupted continuum of our finding the uncommon Kadampa path of the Ganden Oral Lineage instructions, the quickest path to enlightenment of them all.
Within the scope of the heart commitment, I would say there are both common and uncommon promises. The common promises are to (1) cherish the Kadam Dharma, (2) to practice the Kadam Dharma purely without mixing it with other traditions, (3) to share the Kadam Dharma purely without mixing it with other traditions, and (4) to make effort to cause the pure Kadam Dharma to flourish throughout the world.
There are two uncommon promises within our heart commitment to Dorje Shugden. The first is to make the promise to attend every major Kadampa festival (Spring, Summer, and Fall) either in person or on-line between now and at least 2099 (but really, for as long as they last). This functions to preserve the NKT globally for generations to come.
The second uncommon promise of our heart commitment is to keep the Kadampa moral discipline of the Internal Rules of the NKT. These are required if we want to be a Resident Teacher or a center administrator, but are also available to any practitioner. VGL has said they are our most important moral discipline. They are the pinnacle of our Kadampa moral discipline and are taken on the foundation of all the other promises.
None of these promises are imposed upon us from the outside, but are taken freely by the practitioner based upon a clear wisdom that understands benefits of keeping these promises and the dangers of breaking them. All of these promises are worked with gradually and have many levels. When we break them, we can purify the downfall and restore them within our mind. We can do this daily.
We are so lucky to even know of these things, much less have the opportunity to train in them. I would say they are true wishfulfilling jewels.