Choose a day for the Consecration:
To begin, choose the date of a Marian Feast on which to make the consecration. Whichever Feast you choose will determine the date to begin a 33-day period of spiritual preparation, i.e., you follow spiritual exercises for 33 days, and the next day (34th) will be the Marian Feast on which you consecrate yourself. Below is a list of Marian Feasts which are the same on both the traditional and Novus Ordo calendars:
Start of 33-day; ---> Marian Feast You've Chosen ---> Feast/Consecration Day.
9 Jan ---> Apparition of the Immaculate Virgin Mary at Lourdes 11 Feb
20 Feb ---> The Annunciation 25 Mar (start 21 Feb when February has 29 days).
13 Jun ---> Our Lady of Mt. Carmel 16 Jul
13 Jul ---> The Assumption 15 Aug
6 Aug ---> Nativity of the Blessed Virgin Mary 8 Sep
13 Aug ---> Our Lady of Sorrows 15 Sep (Dates selected for this project)
19 Oct ---> Presentation of the Blessed Virgin Mary 21 Nov
5 Nov ---> Immaculate Conception 8 Dec
9 Nov ---> Our Lady of Guadalupe 12 Dec
The Feast of the Annunciation is the Feast that St. Louis de Montfort recommends most of all as it is this Feast that commemorates God Himself taking on flesh and, thereby, subjecting even Himself to trust in and dependency on Our Lady.
First comes a 12-day preparation period that consists of emptying oneself of the spirit of the world in penance and mortification. For those 12 days, we pray the Veni Creator, the Ave Maris Stella, the Magnificat, and the Glory Be.
Then follow 3 weeks, each week having a specific focus.
The first week focuses on offering up our prayers and devotions for the purpose of coming to understand ourselves and our sins; humility is the key, and the prayers the Litany of the Holy Ghost, the Litany of Loreto, and the Ave Maris Stella help us.
During the second week, we ask the Holy Ghost to help us better understand the Blessed Virgin; we pray the Litany of the Holy Ghost, the Litany of Loreto, the Ave Maris Stellis, the prayer to Mary by St. Louis-Marie, and 5 decades of the Holy Rosary each day for assistance.
During the third week, we seek to better understand Christ through meditation and the Litany of the Holy Ghost, the Ave Maris Stella, and the Litany of the Holy Name of Jesus, Montfort's prayer to Jesus, and the prayer O Jesus Living in Mary.