Practice

Make the appropriate minor or major ablution, offer a prayer of two rak‘ats, and ask for His forgiveness.

Abu Bakr (radiAllahu anhu) related from the Messenger of Allah (salAllahu alayhi wasalam) that he said, “There is no one who commits a sin, goes and performs ritual ablutions, and then prays two rakats after which they seek Allah’s forgiveness except that He forgives them.” After this, he (salAllahu alayhi wasalam) recited Allah Most High’s words,

“And those who, when they do an evil thing or wrong themselves, remember Allah and implore forgiveness for their sins - Who forgives sins save Allah only? - and will not knowingly repeat (the wrong) they did.”
[3: 135]

This has been related by Abu Dawud and at-Tirmidhi in their respective Sunan, and the scholars declared it to be a recommended prayer.
[Ibn Qudama, al-Mughni 1.348, Ibn Abidin, Radd al-Muhtar 2.28, quoting Sharh Shir`at al-Islam via Shaykh Isma`il al-Nabulsi]