The sign of the cross is a form of Catholic blessing whereby a person traces a symbolic cross on their body, or in the air in commemoration of the crucifixion of Christ. The sign of the cross is used at the beginning and at the end of a prayer.
Since we make the Sign of the Cross before and after all of our prayers, many don't realize that the Sign of the Cross is not simply an action but a prayer in itself. Like all prayers, the Sign of the Cross should be said with reverence; we shouldn't rush through it on the way to the next prayer.
Using your right hand, you should touch your forehead at the mention of the Father; the lower middle of your chest at the mention of the Son; and the left shoulder on the word "Holy" and the right shoulder on the word "Spirit."
In the name of the Father, and of the Son, and of the Holy Spirit. Amen.