One of the great things about ritual catholicism is that you have recourse to loads of beautiful and eddifying prayers. And you don't have to go to all the trouble of thinking them up yourself. Such are the great "O Antiphons" of Advent. Those of you who say the office, I recommend you print them out and use them at Evensong (in full, before and after the Magnificat). Here is the rubric:
To be said in full before and after Magnificat; or, on Feasts, with V. & R. and Advent Collect after the Collect of the Feast.
In other words, these are antiphons for the Magnificat. And here are the antiphons themselves:
Dec. 16 - O Wisdom, * which camest out of the mouth of the most High, and reachest from one end to another, mightily and sweetly ordering all things: come and teach us the way of prudence.
Dec. 17 - O Adonai, * and Leader of the house of Israel, who appearedst in the bush to Moses in a flame of fire, and gavest him the law in Sinai: come and deliver us with an outstretched arm.
Dec. 18 - O Root of Jesse, * which standest for an ensign of the people, at whom kings shall shut their mouths, to whom the Gentiles shall seek: come and deliver us, and tarry not.
Dec. 19 - O Key of David, * and Sceptre of the house of Israel, that openest, and no man shutteth, and shuttest and no man openeth: come and bring the prisoner out of the prison-house, and him that sitteth in darkness and the shadow of death.
Dec. 20 - O Day-spring, * brightness of light everlasting, and Sun of righteousness: come and enlighten him that sitteth in darkness and the shadow of death.
Dec. 21 - O King of the nations, * and their desire: the Cornerstone, who makest both one: come and save mankind, whom thou formedst of clay.
Dec. 22 - O Emmanuel, * our King and law-giver, the desire of all nations, and their salvation: come and save us, O Lord our God.
Dec. 23 - O Virgin of Virgins, * how shall this be? For neither before thee was any like thee, nor shall there be after. Daughters of Jerusalem, why marvel ye at me? The thing which ye behold is a divine mystery.