What is to be said after wudu’ (ablution)?

1- The Prophet (peace and blessings of Allah be upon him) said, “There is no one among you who does wudu’ properly or does it well, then he says, ‘I bear witness that there is no god except Allah and that Muhammad is the slave of Allah and His Messenger’, but the eight gates of Paradise will be opened to him and he may enter through whichever he wills.” Narrated by Muslim
2- At-Tirmidhi added, “O Allah, make me one of those who repent and make me one of those who purify themselves.”
3- The Prophet (peace and blessings of Allah be upon him) said, “He who does wudu’ and says, ‘Glory and praise be to You, O Allah, I bear witness that there is no god but You, I seek Your forgiveness and I repent to You’, it will be written for him on a parchment, then it will be stamped with a seal which will not be broken until the Day of Resurrection.” Narrated by an-Nisaa’i, and classed as saheeh by al-Albaani

The parchment is thin leather on which to write.

It is an easy act for whom Allah makes it easy, by virtue of which one attains a great reward, so do not neglect it!