Fr. Stefan Heid in an excellent article in Homiletic and Pastoral Review (here) explains why priests should follow the Holy Father's practice of placing a large crucifix in the centre of the altar. Above is a photo the the altar at "my" church, Holy Spirit, Heckmondwike. Some would argue that the crucifix should be facing the people (so that the corpus is seen by them) or that there should be a corpus on both sides. This is wrong, or at least unnecessary. The main purpose in having a cross on the altar in this way is so the priest can face it. In my church, as you can see, there is a large San Damiano cross over the tabernacle. The people can see this, and so it is not necessary for them to see the corpus on the altar cross. I had a supply priest here once who said that he was going to move the cross from the altar because it disturbed the view of the people, who should be able to see the "elements". With respect to my brother priest, this is nonsense. First of all, not everyone in the church can see the chalice anyway, and, in any case, before I installed the cross I tested the view of the altar by walking around to different parts of the church. Although the cross is visible, it does not obscure anyone's view (unless he or she sat in the centre aisle - but even then the actions of the priest can be clearly seen).
There is an important theological/liturgical point to be made here. The priest and people celebrate the Mass facing the cross, not each other. if "Mass facing the people" is meant to be some kind of dialogue (allowing for THE dialogue before the Preface) between the priest and the congregation, then it is clearly a serious mistake. The Mass is celebrated, above all, with reference to The Father. The prayers are addressed almost entirely to The Father (The Kyrie and some of the Communion prayers are not etc), but given the context it is through the Cross that this is possible. The Cross reminds us - and the Father - of the great Sacrifice through which we are redeemed.
The resistance, on the part of some priests and laity, to this emphasis is dangerously mistaken. For this reason (amongst others) I am planning to occasionally pray the Eucharistic Prayer facing in the same direction as the congregation. I am not sure if this will be accepted on Sundays, but I am certainly planning to do this on at least one weekday. This renewed emphasis, taken with the new translation, is so important. Please read the article by Fr. Heid.