"The Messenger of Allaah (sal-Allaahu 'alayhe wa sallam) said: "By Allaah, I seek forgiveness and repent to Allaah, more than seventy times a day."  He (sal-Allaahu 'alayhe wa sallam) also said: "O People, Repent to Allaah! Verily I repent to Him a hundred times a day."  He (sal-Allaahu 'alayhe wa sallam) also said: "Whoever says:
أَسْتَغْفِرُ اللّٰهَ الْعَظِيْمَ الَّذِيْ لَا إِلٰهَ إِلَّا هُوَ الْحَيُّ القَيُّوْمُ وَأَتُوْبُ إِلَيْهِ
"I seek Allaah's forgiveness, besides whom, none has the right to be worshipped except He, The Ever Living, The Self-Subsisting and Supporter of all, and I turn to Him in repentance." 
Astaghfirullaahal-'Adheemal-lathee laa 'ilaaha 'illaa Huwal-Hayyul-Qayyoomu wa 'atoobu 'ilayhi.