St. Louis Marie de Montfort composed this short prayer to Mary as a way to unite your intention with the whole Church before beginning the Holy Rosary.
St. Louis de Montfort’s Prayer to Mary
I unite with all the saints in heaven, with all the just on earth, and with all the faithful here present. I unite with you, my Jesus, in order to praise your holy Mother worthily and to praise you in her and through her. I renounce all distractions which may arise during this Rosary. I desire to say it with attention and devotion as if it were the last of my life. Amen.
For another way to entrust yourself to Mary, see the Act of Consecration to Mary.