Azkaars after obligatory prayer.
Zikr After Obligatory Namaz.
1. Zaid Ibne-Thabit Radiyallahu 'anhu narrates that we were commanded by Rasulullah Sallallahu 'alaihi wasallam to say after every obligatory Salat, Subhanallah (Glory be to Allah who is above all faults) 33 times, Alhamdulillah (Praise be to Allah) 33 times, and Allahu Akbar (Allah is the Greatest) 34 times. One Ansari dreamt that someone asked him: Has Rasulullah Sallallahu 'alaihi wasallam commanded you to say Subhanallah 33 times, Alhamdulillah 33 times, and Alldhuakbar 34 times after every obligatory Salat? He (the Ansari) said: Yes. The voice in the dream said: Make it 25 times each, and add with it, La ilaha illalldh (None is worthy of worship but Allah) 25 times. In the morning, when he went and narrated his dream to Nabi Sallallahu 'alaihi wasallam, the Prophet said: Do so. (Tirmidhi 3413)
Join those who surpassed you
2. Abu Hurairah Radiyallahu 'anhu narrates that once some poor emigrants came to Rasulullah Sallallahu 'alaihi wasallam and said: The rich have attained the highest ranks and eternal bounties of Allah. Rasulullah Sallallahu 'alaihi wasallam said: How is that? They replied: They offer Salat like we offer Salat, and they fast like we fast, and they give charity and we cannot give charity, and they set slaves free and we cannot set slaves free. Rasulullah Sallallahu 'alaihi wasallam said: Should I not teach you something through which you would join those who surpassed you; and keep ahead of those who are after you, and nobody can be better than you unless he also does the same? The Sahabah said: Do tell us. So, Rasulullah Sallallahu 'alaihi wasallam said: Recite Subhanallah, Alhamdulillah, and Alldhuakbar thirty three times each, after every obligatory Salat. Abu Salih said: The poor emigrants returned to Rasulullah Sallallahu 'alaihi wasallam and said: Our rich brothers have heard what we did, and have done the same. Rasulullah Sallallahu 'alaihi wasallam then said: This is Allah's blessing which He bestows on whosoever He wills. (Muslim 1347)
Get the Foam of Sins be forgiven
3. Abu Hurairah Radiyallahu 'anhu narrates that Rasulullah Sallallahu 'alaihi wasallam said: He who recites Subhanallah (Glory be to Allah who is above all faults) 33 times, Alhamdulillah (Praise be to Allah) 33 times and Alldhuakbar (Allah is Greatest) 33 times, which makes a total of 99 times, and then recites once (the following) to complete 100, his sins will be forgiven, even if they are as much as the foam of the sea. None is worthy of worship but Allah, He is One, He has no partner, His is the Kingdom, and for Him is all the Praise, and He has power over all things. (Muslim 1352)