I follow Hanafi way and my answer is as follows:
I have come accross two ways for the same, both have been discussed here,
The tareeqah
which was taught to us by our Ulemah-e-deen
is such that just after finishing your wudhu
, You read

then, You recite the du'a

Then take the water and stand up and drink some, as this is cure for the illnesses.
Then look towards the sky and pray;
سُبْحَانَكَ اللَّهُمَّ وَبِحَمْدِكَ أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا أَنْتَ أَسْتَغْفِرُكَ وَأَتُوبَ إِلَيْكَ
'Subhanaka Allahumma Wa Behamdika Ashhadu An La ilaha illa Anta Astagfiruka Wa Atoobo ilaik' Also recite verses of Surah Al-Qadr
.
2) The ablution (Wuzu) is complete and so pray this Dua,
'Allahummajalni Minattawwabeena Waj'alni Minal Mutahhireen'
Then take the water and stand up and drink some, as this is cure for the illnesses.
Then look towards the sky and pray;
'Subhanaka Allahumma Wa Behamdika Ashhadu An La ilaha illa Anta Astagfiruka Wa Atoobo ilaik' Also pray the Kalima Shahaadat and Sura Inna Anzalna.
May Allah forgive any mistake I would have made in answering this question and give us Hidayat
for following the straight path.
Aameen!! bijahinn sayyidil mursaleen Salallahu alaihi wa sallam