Psychedelic journeys are expansive and can be very intense. It’s important to be ready to relinquish control and give in to whatever may come. Give yourself permission to "go with the flow". Surrender to the experience fully which may include both the pleasant: hysterical laughing fits, awe, profound insights, connection to the universe, overwhelming feelings of love and connection; and the unpleasant: confusion, anxiety, discomfort, and scary or intrusive thoughts.
Fortunately, psilocybin has a very low risk in terms of toxicity and a very high probability for an experience of "spiritual significance". These experiences can offer a deeply peaceful sense of oneness with something much bigger than yourself, and lead to a feeling of intense love and connectedness which is the heart of Unitivist worship.
The most important aspect is what is often referred to as "set and setting. Michael Pollan speaks extensively about this in his book How to Change Your Mind. "Set" refers to an open, calm mindset. Pollan describes a way in which researchers prepared participants was to help them understand that the whole experience is temporary--typically between four and six hours--and that the guide would be protecting your physical body. "Setting" refers to your physical setting. It's fairly common for people to prefer to lay down or enjoy nature. A comfortable, safe setting is key for a positive experience.
James Fadiman once said, “much about our reactions to any stimulus depends on the actual context and the way we perceive it.” Another way to put this, set and setting matter.
Co-founder of the Harvard Psilocybin Project, Timothy Leary, defined set as the mental state a person brings to a psychedelic experience. That is, thoughts, feelings, mood, and desires. Setting he described as the physical and social environment in which a psychedelic experience takes place.
People and places can have a large impact on your journey. This is a main reason why the Unitivist ritual includes the practice of having a trained guide present with you, to ensure your mindset stays focused on the intent of your journey and the setting you are in is comfortable and safe.