Selam alaycom,
The Tasbeeh of Sayeda Fatima
Sayeda Fatima

used to work very hard in her house. Her father our Holy Prophet, Prophet Muhammad

could see how hard she worked.
One day he told her that he was going to give her something that would be better than a helper or anything else in the world.
He gave her Tasbeeh.
He told her that after every Salaat she should say:
Allahu Akbar - 34 times
Alhamdulillah - 33 times
Subhanallah - 33 times
This is what we call the Tasbeeh of Sayeda Fatima.
Prayer is like a beautiful flower and the Tasbeeh of Sayeda Fatima

gives that beautiful flower a beautiful smell.
So after every Salaat we should say the Tasbeeh of Sayeda Fatima

because we want our prayer to be like a beautiful flower with a beautiful smell.
A reliable narration from Imam Baqir

states:
Whoever performed the tasbeeh of Fatima
then asked Allah for forgiveness, Allah forgave him 100 times, added 1,000 good deeds to his scales, repelled the shaytan and Allah was pleased with him.
Imam Sadiq

narrated:
Whoever did the tasbeeh of Fatima
before he unfolded his legs (from the position of sitting in obligational prayer) Allah forgave him and made paradise obligatory upon him.
He also relates:
The tasbeeh of Fatima
in every obligatory prayer is more loved than praying 1,000 rikats every day.
It is related from Imam Sadiq

:
that whoever did the tasbeeh of Fatima
after every prayer, and ended it with la illaha illa Allah, Allah forgave his sins.
It is preferred to use the beads that are made from the turba of Imam Hussein

. A woman should carry prayer beads made of the turba of Imam Hussein

to protect her from adversity.
It is related that Fatima

used to make tasbeeh on her hands, or on a wollen string that was knotted. It was customary to use the hands or string, until Hamza

was killed, upon when it became practice to use clay beads. When Imam Hussein

was killed, it was preferred to use the clay that was from nearby his grave.
Imam Mahdi (ajfrs) has related:
That whoever forgot to make dhikr (remembrance) and in his hand is a rosary of beads made from the turba of Imam Hussein
, reward is written for him.
Imam Sadiq

:
The beads from the grave of Imam Hussein
are counted as tasbeeh on the hand of a man, even if he didn't make the tasbeeh (he only held it).
Imam Sadiq

also related:
Whoever did the tasbeeh with the turba of Hussein
once, Allah counted it for him 70 times, and when he touches the beads with his hand and doesn't do tasbeeh with it, for each bead he touches, the reward is 7 times.
Another narration says that for each bead is 40 hasanat.
A reliable tradition from Imam Musa

states:
The true believer is not without five things: a miswak, a comb/brush, a prayer rug, tasbeeh beads and an aqiq ring.
It is related from Imam Sadiq

:
Whoever did tasbeeh on the clay beads from the grave of Imam Hussein
Allah wrote for him 400 good deeds, and erased from him 400 bad deeds, and met 400 of his needs and raised him 400 degrees/ levels.
The narrations recommend that the string the beads are threaded on be
blue in color.
It is narrated from Al Burqy from Imam Sadiq

:
Whoever did the tasbeeh 10 times after his obligatory prayer and before he moved his legs from his place, Allah erased from him 400 thousand thousand bad deeds and wrote for him 400 thousand thousand good deeds, and it is if he read the Holy Quran 12 times. Then he said:
I myself don't move my legs (from the sitting position after prayer) without saying it 100 times, but for you, say it (only) ten times.
Peace,
Um Ali
2:184. O ye who believe, fasting is prescribed for you, as it was prescribed for those before you, so that you may guard against evil.