What are these universal principles? First and foremost, there is the concept that consciousness is the very fabric of all manifestation, pervading all of the universe, including yourself. The characteristics of that universal consciousness (before conditioning obscures and distorts them) are spaciousness, luminosity and awareness. People call this consciousness God or Buddha-nature. I like to use the word Universe.
The second principle is that this universal consciousness is reliable, that what arises from it obeys certain laws which are consistent whether one is observing the smallest particles or the vastness of space. These laws, or universal truths, can be experienced as direct insights by human beings who have prepared themselves by a disciplined and sustained approach to purification of the obscurations and distortions. Over the course of human history methodic systems have been taught by those who have had such direct experiences. Some of these teachings, and the realizations which arise from them, have been passed down, conceptually and experientially, from teacher to student without interruption from the person who had the original experience of transcendence. We have access today to these same lines of direct transmission.
The third principle is that our struggle to learn and to grow is supported by Universe. However isolated we may feel, we are part of a vast, interconnected web of consciousness -- some of which manifests in form, and is therefore perceivable to our physical senses; some of which exists as vibrations or force fields of energy which we are capable of experiencing directly if we train our latent capacities of consciousness. If we are fortunate, and our motivation over lifetimes has been wholesome and sincere, we may meet "real-time" teachers and teachings which will provide us with the tools we need to explore the various laws of universe and come to our own direct experience of the spacious, luminous, aware consciousness which sustains our existence. We may experience the synergy of communities of like-minded people who share these higher aspirations.
These three principles -- Universe, Law, and Interconnectedness -- are sometimes referred to as refuge -- a safe, reliable conceptual platform from which we can investigate with confidence. We can enhance our practice of meditation -- no matter what our personal motivation is -- by pondering these three principles again and again as concepts, by aspiring through our meditation practice to come to a direct realization or knowing of these truths for ourselves.