tolkiens legendarium - What was in the One Ring that made it so powerful?

In the movie version of Fellowship of the Rings, at the beginning of film, we're shown all the rings being forged, including Sauron's One Ring of power. However, there's no indication as to what Sauron did to that ring in order to make it so powerful, omnipotent, and extraordinarily evil. Did he conduct a spell? Sacrifice a poor maiden? Channel evil and malevolent spirits in order to make the ring so powerful and to have a sentient connection with Sauron? The ring was almost loyal, an interesting trait for an inanimate object.

How did Sauron create the One Ring with such an essence of malice, evil, and power?

Answer

From Wikipedia:

The One Ring was created by the Dark Lord Sauron during the Second Age in order to gain dominion over the free peoples of Middle-earth. In disguise as Annatar, or "Lord of Gifts", he aided the Elven smiths of Eregion and their leader Celebrimbor in the making of the Rings of Power. He then forged the One Ring himself in the fires of Mount Doom.

Sauron intended it to be the most powerful of all Rings, able to rule and control those who wore the others. Since the other Rings were themselves powerful, Sauron was obliged to place much of his own power into the One to achieve his purpose.

I think putting a part of himself in the ring made it the dominating ring. Also, remember that when he lost it in the battle, Sauron became very weak.