Well, after reading two or three spells of the same name on here I must say I am very disappointing. Not a single person on here has taken the time to include the herbal requirements for the spell as listed per the popular T.V. show "Charmed" where this spell originates. Having read through this spell a few times I can tell you if you include the herbal information and keep your focus strong this spell WILL work. It is simple, yet powerful. Especially when emotion is attached to it, as with all magic.
"In a morter and pestle grind these three ingrediants:
A pinsh of Rosemary
A sprig of Cyprus,
A Yarrow root
Grind while chanting:
"Powers of the witches rise,
course unseen across the skies,
Come to us who call you near,
come to us and settle here.
Spill the blood of the caller into the morter and continue chanting, saying:
"Blood to blood I summon thee,
blood to blood return to me."
That is the full spell as written in the Warren/Halliwell Book of Shadows. Now I will say this much in warning. If you are not calling a family member I would avoid the blood to blood chant, however I would definitely discharge a few drops of blood, as this shows the Gods your willingness to make a sacrifice for your will to manifest.