A common Roman Catholic prayer to St Jude is:Wikipedia
"O most holy apostle, Saint Jude, faithful servant and friend of Jesus, the Church honoureth and invoketh thee universally, as the patron of hopeless cases, and of things almost despaired of. Pray for me, who am so miserable. Make use, I implore thee, of that particular privilege accorded to thee, to bring visible and speedy help where help was almost despaired of. Come to mine assistance in this great need, that I may receive the consolation and succor of Heaven in all my necessities, tribulations, and sufferings, particularly (here make your request) and that I may praise God with thee and all the elect throughout eternity. I promise thee, O blessed Jude, to be ever mindful of this great favour, to always honour thee as my special and powerful patron, and to gratefully encourage devotion to thee. Amen."An alternative prayer:"May the Sacred Heart of Jesus be adored, glorified, loved and preserved now and forever. Sacred Heart of Jesus have mercy on us, Saint Jude worker of Miracles, pray for us, Saint Jude helper and keeper of the hopeless, pray for us, Thank you Saint Jude."Novena to Saint Jude (Novenas are a prayer said for nine consecutive days):"O Holy St Jude!
Apostle and Martyr, great in virtue and rich in miracles, near kinsman of Jesus Christ, faithful intercessor for all who invoke thee, special patron in time of need; to thee I have recourse from the depth of my heart, and humbly beg thee, to whom God hath given such great power, to come to my assistance; help me now in my urgent need and grant my earnest petition. I will never forget thy graces and the favors thou dost obtain for me and I will do my utmost to spread devotion to thee. Amen."