I love Blessed Mother Teresa's "Flying Novena. In an emergency, just pray the Memorare prayer nine times for whatever is causing you stress or worry, knowing that your heavenly mother will intercede in prayer for you.
The Memorare prayer reminds us that the Blessed Virgin Mary is ready to help us when needed if we approach her with love, true contrition for our sins, and a sincere desire to do Her son’s will.
Jewish man who hated the Catholic faith, accepted the challenge to wear the Catholic miraculous medal and say the Memorare for 9days. He did not even know any Jewish prayers, and he wrote the Memorare down. When he went into the Church to pray, the Virgin Mother spoke to him and he wanted to be baptized Catholic immediately. The miracle of doing one act of honoring the Blessed Mother was fulfilled.
The Memorare and Prayer For The Souls in Purgatory. Mother Theresa would recommend to pray the Memorare as a Novena. I have since begun to do this from time to time, even to praying it over and over again several times.