What happens after Consecration? (GIRM 151). After the Consecration when the Priest has said, The mystery of faith, the people pronounce the acclamation, using one of the prescribed formulas. At the end of the Eucharistic Prayer, the Priest takes the paten with the host and the chalice and elevates them both while pronouncing alone the doxology Through him. At the end the people acclaim, Amen. After this, the Priest places the paten and the chalice on the corporal.

When and how do we pray the Lord’s Prayer? (GIRM 152&153) After the Eucharistic Prayer is concluded, the Priest, with hands joined, says alone the introduction to the Lord’s Prayer, and then with hands extended, he pronounces the prayer together with the people. After the Lord’s Prayer is concluded, the Priest, with hands extended, says alone the embolism Libera nos (Deliver us, Lord). At the end, the people acclaim, For the kingdom. (GIRM 81) The Our Father; The invitation, the Prayer itself, the embolism, and the doxology by which the people conclude these things are sung or are said aloud.

When and how do we give the Sign of Peace? Then the Priest, with hands extended, says aloud the prayer Domine Iesu Christe, qui dixisti (Lord Jesus Christ, who said to your Apostles) and when it is concluded, extending and then joining his hands, he announces the greeting of peace, facing the people and saying, The peace of the Lord be with you always. The people reply, And with your spirit. 

Do we have to give the Sign of Peace to each other at Mass? After this, if appropriate, the Priest adds, Let us offer each other the sign of peace.

Where should the Priest be during the Sign of Peace? The Priest may give the Sign of Peace to the ministers but always remains within the sanctuary, so that the celebration is not disrupted. In the Dioceses of the United States of America, for a good reason, on special occasions (for example, in the case of a funeral, a wedding, or when civic leaders are present), the Priest may offer the Sign of Peace to a small number of the faithful near the sanctuary. According to what is decided by the Conference of Bishops, all express to one another peace, communion, and charity.

What are the people supposed to say during the Sign of Peace? While the Sign of Peace is being given, it is permissible to say, The peace of the Lord be with you always, to which the reply is Amen. (GIRM 82) As for the actual sign of peace to be given, the manner is to be established by the Conferences
of Bishops in accordance with the culture and customs of the peoples. However, it is appropriate that each person, in a sober manner, offer the sign of peace only to those who are nearest.

What is the Priest doing during the Agnus Dei? (GIRM 155 & 156, 83) After this, the Priest takes the host, breaks it over the paten, and places a small piece in the chalice, saying quietly, Haec commixtio (May this mingling). The Priest breaks the Bread and puts a piece of the host into the chalice to signify the unity of the Body and Blood of the Lord in the work of salvation, namely, of the Body of Jesus Christ, living and glorious.  [83] The fraction or breaking of bread is begun after the sign of peace and is carried out with proper reverence, and should not be unnecessarily prolonged or accorded exaggerated importance. This rite is reserved to the Priest and the Deacon.

Why should the fraction rite not be “prolonged or exaggerated importance”?

How should the Agnus Dei, be prayed? (GIRM 83) The supplication Agnus Dei (Lamb of God) is usually sung by the choir or cantor with the congregation replying; or at least recited aloud. This invocation accompanies the fraction of the bread and, for this reason, may be repeated as many times as necessary until the rite has been completed. The final time it concludes with the words grant us peace.

What do the Priest and People do after the Agnus Dei? (GIRM 156-159) Then the Priest, with hands joined, says quietly the prayer for Communion, either Domine Iesu Christe, Fili Dei vivi (Lord Jesus Christ, Son of the living God) or Perceptio Corporis et Sanguinis tui (May the receiving of your Body and Blood). When the prayer is concluded, the Priest genuflects, takes a host consecrated at the same Mass, and, holding it slightly raised above the paten or above the chalice, facing the people, says, Ecce Agnus Dei (Behold the Lamb of God) and together with the people he adds, Lord, I am not worthy. After this, standing facing the altar, the Priest says quietly, Corpus Christi custodiat me in vitam aeternam (May the Body of Christ keep me safe for eternal life), and reverently consumes the Body of Christ. Then he takes the chalice, saying quietly, Sanguis Christi custodiat me in vitam aeternam (May the Blood of Christ keep me safe for eternal life), and reverently partakes of the Blood of Christ.