Most of the Psalms of Night Prayer are petitions for God's help combined with expressions of hope and trust in His merciful love. It is natural to pray these psalms in our own voice, and on our own behalf. They are so fitting as our last prayers of the day.
But it's also a good idea to think about Our Lord praying these prsalms, calling upon His Father to help Him, protect Him from enemies, and preserve Him from death. Tonight's (Thursday's) night psalm, 16, is a perfect example. In fact, as John Brook's School of Prayer points out, this is the earliest example of the Church seeing in a psalm a direct prophetic reference to our Redeemer: St. Peter refers to it in the book of Acts. (2: 30-31).
Preserve me, God, I take refuge in you. I say to the Lord: “You are my God. My happiness lies in you alone.”
He has put into my heart a marvelous love for the faithful ones who dwell in his land. Those who choose other gods increase their sorrows. Never will I offer their offerings of blood. Never will I take their name upon my lips.
O Lord, it is you who are my portion and cup; it is you yourself who are my prize. The lot marked out for me is my delight: welcome indeed the heritage that falls to me!
I will bless the Lord who gives me counsel, who even at night directs my heart. I keep the Lord ever in my sight: since he is at my right hand, I shall stand firm.
And so my heart rejoices, my soul is glad; even my body shall rest in safety. For you will not leave my soul among the dead, nor let your beloved know decay.
You will show me the path of life, the fullness of joy in your presence, at your right hand happiness for ever.
It's even more moving to imagine Jesus praying Friday night's psalm, 88, in the Garden of Gethsemane:
Lord, why do you reject me? Why do you hide your face?
Wretched, close to death from my youth, I have borne your trials; I am numb. Your fury has swept down upon me; your terrors have utterly destroyed me.
They surround me all the day like a flood, they assail me all together. Friend and neighbor you have taken away: my one companion is darkness.
Examples such as these really bring home how the liturgy truly is Christ praying to the Father , and mercifully allowing us,members of His body, to join our voices to His.