Catholics, being in a state of grace, can gain a Plenary Indulgence by many different prayers and works of piety.
The following are worthy of special mention;
A partial indulgence is granted the Christian faithful when they visit the Blessed Sacrament for the purpose of adoration. When this is done for at least half an hour, the indulgence is a plenary one.
An indulgence, applicable only to the Souls in Purgatory, is granted to the faithful, who devoutly visit a cemetery and pray, even if only mentally, for the departed.
The indulgence is plenary each day from the 1st to the 8th of November; on other days of the year it is partial.
Eternal rest grant to them, O Lord, and let perpetual light shine upon them. May they rest in peace. (Roman Breviary)
A plenary indulgence is granted when the rosary is recited in a church or oratory or when it is recited in a family, a religious community, or a pious association. A partial indulgence is granted for its recitation in all other circumstances. (The rosary is a prayer formula divided into fifteen decades of Hail Mary's with the Lord's Prayer separating each of these decades. During each of these decades we recall in devout meditation the mysteries of our redemption.)
It has become customary to call but five such decades the Rosary also. Concerning this customary usage then, the following norms are given as regards a plenary indulgence.
1. The recitation of a third of the rosary is sufficient for obtaining the plenary indulgence, but these five decades must be recited without interruption.
2. Devout meditation on the mysteries is to be added to the vocal prayer.
3. In its public recitation the mysteries must be announced in accord with approved local custom, but in its private recitation it is sufficient for the Christian faithful simply to join meditation on the mysteries to the vocal prayer.
4. In the Eastern Churches where recitation of the Marian rosary as a devotional practice is not found, the patriarchs can establish other prayers in honor of the blessed Virgin Mary which will have the same indulgences as those attached to the rosary, (e.g., in the Byzantine churches, the Akathist hymn, or the office Paraclisis.)*
A partial indulgence is granted the Christian faithful who read sacred scripture with the veneration due God's word and as a form of spiritual reading. The indulgence will be a plenary one when such reading is done for at least one-half hour. partial indulgence, applicable only to the souls in purgatory.
A plenary indulgence is granted the Christian faithful who devoutly make the Stations of the Cross. This devout exercise of the Stations of the Cross helps renew our remembrance of the sufferings that our divine redeemer underwent on his journey from Pilate's praetorium, where he was condemned to death, to Mount Calvary, where for our salvation he died on the cross.
The norms for obtaining this plenary indulgence are the following:
1. This devout exercise must be performed before stations of the cross that have been lawfully erected.
2. Fourteen crosses are required in order to erect the Stations of the Cross. As an aid to devotion these crosses are customarily attached to fourteen tableaux or images representing the Jerusalem stations.
3. In accord with the more common custom, this devout exercise consists of fourteen pious readings to which are joined some vocal prayers. But in order to perform this devout exercise it is required only that one devoutly meditate upon the passion and death of the Lord. It is not required that one meditate upon each of the individual mysteries of the stations.
4. Movement from one station to the next is required. If this devout exercise is carried out publicly and such movement by all present cannot be done without some disorder, it is sufficient that the person who is leading the exercise move from station to station while the others remain in their places.
5. Persons who are legitimately prevented from fulfilling the above requirements can obtain this indulgence if they at least spend some time, e.g., fifteen minutes, in devout reading and meditation upon the passion and death of our Lord Jesus Christ.
6. Equivalent to this devout exercise of the Stations of the Cross — even with regard to obtaining the indulgence — are those other devout exercises which have been approved by competent authority and which call to mind the remembrance of the Lord's passion and death in a manner similar to the Stations of the Cross.
7. In order to obtain this indulgence, the patriarchs can establish some other devout exercise in memory of the passion and death of our Lord Jesus Christ for those Eastern Christian faithful whose usages do not include this exercise of the Stations.
A plenary indulgence, applicable only to the Souls in Purgatory, is granted to the faithful, who on the day dedicated to the Commemoration of all the faithful departed, piously visit a church, a public oratory or — for those entitled to use it — a semipublic oratory.
The above indulgence can be acquired either on the day designated above or, with the consent of the Ordinary, on the preceding or following Sunday or the feast of All Saints.
The above indulgence is contained in the Apostolic Constitution The Doctrine of Indulgences, Norm 15, with account being taken of proposals made to the Sacred Penitentiary in the meantime.
In visiting the church or oratory, it is required, according to Norm 16 of the same Apostolic Constitution, that (1) Our Father and the Creed be recited.