Ok, one loony cult coming right up. I went with an Egyptian theme, it gives the impression of age, and cool magic stuff is associated with Egypt, so that should give us a good base for attracting members.
Children of Wadjet
Who we are and what we believe:
The Children of Wadjet are dedicated to the ancient Egyptian snake goddess Wadjet.
In ancient times Wadjet was worshiped of Egyptian Pharoahs. By following her teachings, they ruled the kingdom wisely, and ultimately grew wise enough for their souls were able to transcend death itself and reach immortality. For thousands of years, Egypt was led in this manner and prospered. However, the forces of evil eventually weakened their devotion, and they abandoned her. She cursed the Egyptians, dooming them to destruction at the hands of their enemies. In their pride, the Pharoahs did not beg her forgiveness. Instead, the pharoahs killed her priests, and destroyed the scrolls containing all her spells and knowledge. However, one faithful priest was able to hide the scrolls in a secret chanber of the valley of the kings before he was murdered. Shortly after this, barbarians destroyed Egypt. For thousands of years the scrolls lay hidden, until they were discovered in 1923 by Nazi archeologists. During the fall of Nazi Germany, the scrolls were looted by an American soldier, and lay in an attic for decades. Until they were discovered by Evil Tyrant. Wadjet then appeared to him, and promised her blessing to him, and all who would worship her.
Organisation
High Priest: Wadjet speaks directly to him, and he commands all others.
Priests/Priestesses: Lower down on the food chain, they help me run things, and ensure that Wadjet's idol is never unattended.
Acolytes: Everyone else who worships Wadjet and supports her priests/priestesses.
Rituals
Basic worship of Wadjet: A gold idol of a nude female with an Egyptian hairstyle. The idol will be clothed with specially made clothing based on ancient Egyptian clothes. Incence must be burned in the sanctuary at all times, and there will be frequent animal sacrifices. The only human sacrifice will be if anyone tries to leave the cult. If that happens, they will be kidnapped, drugged, and sacrificed to appease Wadjet for the apostasy.
Snake Handling: Snakes are beloved to Wadjet, so snake handling is something all priests/priestesses must learn.
Initiation: Initiates must swear an oath to serve Wadjet for eternity, this is to be sealed by slitting their wrist, draining out some blood. The blood is mixed with red wine and incence, then drank by the initiate.
Basic Moral Teachings
Good and evil: All who do not follow the cult are servants of evil. In her mercy, Wadjet is willing to forgive those who abandon their ways and follow her. Those who are non believers mayt be killed, robbed, or otherwise harmed if it is done to advance the worship of Wadjet.
Sex: Prohibited with servants of evil. Within the cult, free sex is not only permitted, but encouraged.
Apostasy: If anyone is seduced back into the service of evil, there will be no mercy for him.
Personal possessions: All personal belongings must be donated to Wadjet, and will be used in common by all members.
Financing: Donations from new members. Some more charismatic members will be promoted to the priesthood, and search for missionaries. Ideally, we should aim for rich imbecils as our main objective. Possibly the cult might be modifed to worship some sort of sex goddess, and if the compound was in Nevada, we could run a brothel.
Cult location/place of worship: Not sure how this will be organised yet. An isolated compound with the main temple would be good.
Security: Since the forces of evil seek to destroy us, we will be armed to the teeth. However, such things will be done clandestinely, don't want to be another Waco.
A fine cult, if I do say so myself. But this is just a basic outline. If I ever get around to actually founding a cult, I will have to put more thought into fleshing out it's beliefs a bit. BTW: I know there is almost no truth to the Egyptian history bit, but I imagine most of the cult members won't be smart enough to figure that out.