Hakim al Umma Moulana Ashraf Ali Thanwi (Allah have mercy on him) once mentioned:

One method which I prescribe to people for leaving out sins, is that every night before sleeping, one should seclude oneself in a room and sincerely supplicate to Allah to forgive him for his sins. One should make du’aa to Allah in the following manner: “O Allah! I am an extremely sinful servant! I am not worthy of any good and I am full of weaknesses!” Through these words, one should express one’s true condition of sinfulness before Allah. Thereafter, one should say, “O Allah! I do not have the courage and resolve to leave out these sins! It is only You who can assist and help me to leave out these sins!”

If one adopts this method, then insha Allah, in a week or two, he will be blessed with the facilitation (taufeeq) and ability to leave out these sins. However, very few people are willing to sincerely repent to Allah in this manner.

(Malfoozaat Husn-ul-Azeez pg. 226)