The Popes of the last 150 years (from Bl. Pius IX through Bl. John Paul II and Pope Benedict XVI) have taught the Catholic Church that the best and highest form of devotion to the Blessed Virgin Mary is total consecration to Mary.
Total consecration means that one consecrates himself to the Mother of God to become an instrument and tool in her immaculate hands. You become a servant of Christ the King more perfectly by allowing Mary to form you for His Divine Purposes. All of your prayers, works, penances, and received indulgences are committed to her care and discretion for the greater glory of God.
We do this by either performing the St Louis de Montfort 33 day consecration or the St Maximilian Maria Kolbe consecration. St Maximilian invites to consecrate ourselves to Mary by wearing the Miraculous Medal, praying the Rosary daily, enrolling in the Militia Immaculata (or even the MIM of the Franciscans of the Immaculate) and solemnly reciting the following prayer of consecration on a Feast Day of our Immaculate Queen after having gone to confession and receiving Holy Communion:
23 Jan Espousals of Joseph and Mary
11 Feb Immaculate Virgin Mary at Lourdes
25 Mar The Annunciation
16 Jul Our Lady of Mt. Carmel
15 Aug The Assumption
8 Sep Nativity of the Blessed Virgin Mary
15 Sep Our Lady of Sorrows
21 Nov Presentation of the Blessed Virgin Mary
8 Dec Immaculate Conception
12 Dec Our Lady of Guadalupe
Having chosen the day and prepared accordingly with Confession, Communion, and acts of penance, receite the following consecration:
O Immaculata, Queen of Heaven and earth, refuge of sinners and our most loving Mother, God has willed to entrust the entire order of mercy to thee. I, N___, a repentant sinner, cast myself at thy feet humbly imploring thee to take me with all that I am and have, wholly to thyself as thy possession and property. Please make of me, of all my powers of soul and body, of my whole life, death and eternity, whatever most pleases thee. If it pleases thee, use all that I am and have without reserve, wholly to accomplish what was said of thee: "She will crush your head," and, "Thou alone have destroyed all heresies in the whole world."
Let me be a fit instrument in thine Immaculate and merciful hands for introducing and increasing the maximum in all the many strayed and indifferent souls, and thus help extend as far as possible the blessed Kingdom of the most Sacred Heart of Jesus. For wherever thou enters, one obtains the grace of conversion and growth in holiness, since it is through thy hands that all graces come to us from the most Sacred Heart of Jesus.
V. Allow me to praise thee O Sacred Virgin.
R. Give me strength against thy enemies.
6 Paters, 6 Aves, and 6 Glorias for the intentions of the Pope
If the steps above are followed, a Plenary Indulgence is received. If there is attachment to venial sin, a partial indulgence is received instead.
Wear the Miraculous Medal piously and seek St Maximilian's prays often. Welcome to the legions of Mary's soldiers. Fight valiantly and live humbly for the glory of Christ the King.