There is a traditional Catholic prayer that I only learned a few years ago that has become a great comfort for me. It is called the Saint Gertrude's Prayer. Saint Gertrude was said to have been given this prayer by Christ in a vision along with the promise that saying it would free a thousand souls from Purgatory.
Eternal Father,I offer Thee the Most Precious Blood of Thy Divine Son, Jesus, in union with the Masses said throughout the world today, for all the Holy Souls in Purgatory, for sinners everywhere, for sinners in the Universal Church, those in my own home and within my family.
This prayer has become important to me not only as more of my family members pass away from this life, but also as I age and realize that sinners are everywhere--in my family, among my co-workers and in the Church.
This time of year, when the Church asks us to remember those who have died and think a bit on our own passing, the Prayer of St. Gertrude is a good prayer to remember to say.