The celebrant and attendants face the altar for the Introit. The celebrant kisses the altar upon arrival.
My variation: At the intonation of the Introit, the celebrant begins his approach to the altar from the lowest point. He makes the sign of the cross upon himself three times: first, at his first step, second, pausing briefly at the rail, and third, upon arrival at the altar, whereupon he genuflects and, laying both hands flat upon the altar, kisses it. During the Gloria Patri he (and all) also bows for Glory be to the Father and to the Son and to the Holy Ghost.