I am assuming you've read the previous articles on energy, elements, and the elemental triplicities. If you haven't, I recommend starting there and coming back.
The central metaphor of pisces is a fish delving deep in the ocean. This is the process of delving the occult, or of entering god's orchard.
Cancer feels the feelings associated with trauma. Once the feelings have been processed, Scorpio is free to put a microscope to one's feelings to explain why and how we feel the way we do. When Pisces comes into the fold, there is no further need to feel what has been felt, to explain what has been explained. Pisces, therefor, is tasked with the final role of the grieving process: acceptance. Water healing is the permanent resolution of a trauma. It does not negate the trauma, nor does it allow us to entirely forget that the trauma has occurred. Instead, Pisces allows us to psychologically distance ourselves from the trauma and to treat it as a page long ago turned.
We are capable of experiencing more than we generally do. It is the ego which acts the lens for our mental camera. Through this lens, information from the external world is warped and focused into meaningful patterns. Unconsciously, we perceive a separateness about the world that divides it into distinct entities. In some edge cases, such as the ship of Theseus philosophers propose theoretical objections to this base component of each ego. However, Pisces does not argue with this lens on a theoretical level. The mental camera of the mind is stripped of its lens, this is known as ego death. Ego death can be induced by substances or extreme trauma, but I will be focusing on the voluntary and willful triggering of ego death through Piscean energy.
One sits or lays in a comfortable position and enters a receptive meditative state. If there are noises, one acknowledges them and lets them go on. They focus on the here, the now, their extremities, their breathing. Through entering this meditative state, one empties their mind to a large extent. In inner child meditations, one switches perspective between inner child and parent rapidly enough to trick the brain into identifying as both child and parent so that one speaking to the other is experienced simultaneously from both sides. This, however, only approaches ego death, and is not the same thing.
To achieve ego death via meditation, one applies stimuli to the mind. This may come as chanting, breathing, or as guided meditation with another guiding one's train of thought. Whichever route, the key is for the mind to busy itself with processing this noise while relaxing deeply enough to fully occupy your ego and allow it to fade to the background. The resulting ecstasy state evade accurate description. Suffice it to say that there are many paths to this state, from the Sufi, to the Zen Buddhist, Thelemite, Kabbalist, Wiccan, and Chaos Magickian. I identify most closely with the latter, and will lay out the method I have personally found success.
The times I was able to willingly enter ego death. After performing the Qabalistic Cross and Lesser Banishing Ritual of the Pentagram, I lit a candle bearing the symbol of the moon and ran a hot bath, turning out the lights. The room was almost perfectly dark and silent. After entering my mind palace, I consulted a tulpa of Luna(the moon) and allowed her to guide my conscious thoughts. After a certain amount of time, I blew out the candle and opened my eyes. My mind palace fell away into darkness, and my mind entered an ecstatic state.
The eldest son set out to bring riches back to his poor, struggling family of fishers. He made a makeshift raft and paddled it out to sea, where it was pulled into a storm. He awoke washed up on an island. Everywhere around him, diamonds and gems the size of his fist lay on the ground. He quickly gathered these precious stones in his arms and ran to the nearest town to sell them. When he arrived at a trader, the trader rolled his eyes and informed the son that in this land, diamonds and gems were so common that they were worthless and littered the streets as garbage. What people on this island truly valued, however, were onions. The trader gave the son an onion as charity, and the son planted it. Over the next couple years he became a very successful onion farmer, amassing a fortune and becoming one of the most wealthy on the island. One day, he decided to bring back his hoard of riches to his family, so he purchased raft and filled it to the brim with every onion he owned. He sailed a long time, and the onions began to go smell. When he arrived at the shore, his father spotted him and ran to him. "Son, why have you been away for so long? What have you been doing?" His son hopped off the raft and proudly pointed to his treasures aboard the raft. "I found an island with diamonds everywhere, made a great fortune, and brought that fortune back!" The father, with a look of disbelief, looked between the raft of onions and his son. "Why did you bring us moldy onions? Why didn't you bring any diamonds?!" The moral of this story is that when one ventures into the occult, they must be mindful of what they wish to take away from it and what use that will be for others.