Unless the profound techniques of the Vajrayana are being supported by bodhicitta one will not necessarily make meaningful realizations. So, you see, that everything is actually rooted in the practice of bodhicitta, and to pursue with sincerity whatever enhances and supports the practice of bodhicitta creates favorable situations for its development. An example of a means to develop bodhicitta is Pratimoksa. In the Pratimoksa tradition there are seven families or levels of Pratimoksa, or self-discipline. These are known as the precepts or vows.
Refuge is the most important prerequisite to enter into the practice of discipline.
After taking refuge, you take whatever other precepts you can. Keeping them strengthens your practice of bodhicitta, and enables you to tread on the path of Buddhadharma more simply, sincerely and sanely. The importance of the application of self-discipline, the precepts, must not be neglected. If one is to uproot these patterns and to apply the proper antidote for these poisons, the practices of discipline as outlined in the Pratimoksa are necessary tools. Then we have the Mahayana principles.