SEEKING PARDON

Seeking Divine pardon is an antidote for the poisoning of human soul by sinning. Every sin against Allah,  however heinous 'if may be, is forgiven if one seeks Divine pardon for it. Whenever a sin-great or small-is  committed, it should be atoned for by seeking pardon, and even when no sin has been apparently committed, one should seek Divine forgiveness. Every Muslim knows that the eternally blessed Prophet Muhammad was  free of all sin, but even then he has said that "I beg for Allah's forgiveness seventy times or more every day.
(Bukhari)

In one hadith the eternally blessed Prophet is quoted as follows: "Whosoever regularly seeks Allah's pardon,  Allah makes for him a way out of all tight corners, removes all his worries and grants him sustenance from  sources he had never imagined ("Abu Daud, Kitab-al-Satat. Bab-al-Istighfar") .

Hence one should cultivate the habit of seeking Divine pardon at all times and at least once a (lay, one should  tell a hundred beads of Istighfar on the rosary. 

 سيد الاستغفار

 One can ask for-Divine forgiveness in any language however the Arabic version is givin below

  اَسْتَغْفِرُ اللهَ رَبِّىْ مِنْ كُلِّ ذَنْۢبٍوَاَتُوْبُ اِلَيْهِ

One particular form of seeking Divine pardon has been particularly lauded in hadith, and it has been designated  as Chief of all Prayers for Divine Forgiveness; it is given below

اللّهـمَّ أَنْتَ رَبِّـي لا إلهَ إلاّ أَنْتَ ، خَلَقْتَنـي وَأَنا عَبْـدُك ، وَأَنا عَلـى عَهْـدِكَ وَوَعْـدِكَ ما اسْتَـطَعْـت ، أَعـوذُبِكَ مِنْ شَـرِّ ما صَنَـعْت ، أَبـوءُ لَـكَ بِنِعْـمَتِـكَ عَلَـيَّ وَأَبـوءُ بِذَنْـبي فَاغْفـِرْ لي فَإِنَّـهُ لا يَغْـفِرُ الذُّنـوبَ إِلاّ أَنْتَ

Translation: 0 Allah! You are my Sustainer there is no god but You, You created me, I am Your bondsman and am to the best of my ability firm on my oath to You. I seek refuge with You against whatever I have done.  Whatever boons You have showered on me, I invoke them and turn to You and i also turn to You against my sins. Hence forgive my sins because there is none save You who forgives sins

Hadith tells us that whosoever intones these words with full faith in the morning and dies before - nightfall shall  be counted among those of the Paradise  and whosoever says them with full faith at night and dies before morning shall likewise go to paradise. (Sahih Bukhari, Bab Afdal-a!-Istighfar

Specially before going to sleep, one should briefly recall one's shortcomings and wrongdoings of the day
and seek Divine Pardon for them and Grace