Bismillahir Rahmaanir Raheem
Hadhrat Salmaan (Radhiyallahu ‘anhu) related that Rasulullah Sallallaahu ‘alayhi wasallam delivered a sermon on the last day of the month of Sha’baan. In it, Rasulullah Sallallaahu ‘alayhi wasallam said:
“And in this month (Ramadaan), four things you should continue to perform in great number; two of which shall be to please your Lord, while the other two shall be those which you cannot do without.
Those which shall be to please your Lord are:
That you should in great quantity bear witness that there is no deity to worship except Allah (i.e. recite the Kalimah Tayyibah, Laa ilaha illallah)
and make much Istighfaar (repentance, beg Allah Ta’ala’s forgiveness with Astagfirullah).
And as for those which you cannot do without:
You should beg of Allah Ta’ala, entrance into Paradise and ask refuge in Him from Jahannum.”
The following is a simple Zikr which encompasses all of the above four and should be read daily and frequently in the month of Ramadaan, as per the guidance of our Beloved Rasul Sallallaahu ‘alayhi wasallam. May Allah Ta’ala grant us the Taufeeq.
 Reported by Ibn Khuzaimah in his Saheeh