The scholars have enlisted many practices for boosting the memory, however most of these practices are based on experience and are not from the Hadith. There is no harm in practicing upon these as long as one is aware of the above.
My Honourable teacher, Al-Muhaddith Shaykh Muhammad ‘Awwamah (may Allah protect him) usually recommends -among other things– the following salat on Nabi (sallalahu ‘alayhi wasallam) to be recited frequently daily between Maghrib and ‘Isha Salah:
Here under are more such practices:
Actions or foods that strengthen the memory
1. The correct Intention.
2. Practicing upon the acquired knowledge.
3. Propagating knowledge.
4. Muzakarah/Takrar (discussions) of knowledge.
5. To revise the lesson in one’s mind.
6. Writing / to take notes.
8. To scent a good fragrance.
11. Cow’s milk.
12. Rose water.
14. Resin of Mastic tree.
15. To eat and drink less.
17. Reciting the Holy Quran while looking into it.
18. Reciting the first four verses of Surah Baqarah, Ayatul-Kursi, with the two verses that follow it and the last three verses of Surah Baqarah before sleeping.
19. Sallutations upon Rasulullah (sallallahu ‘alayhi wasallam)- as directed above-
20. Salatul hifz.
Imam Bukhari (rahimahullah) was once asked as to what was most beneficial for increasing the memory, he replied:
21. True greed for knowledge, and
22. Persistent mutala’ah (studying).
Imam Shafi’i (rahimahullah) had prescribed the following four methods:
23. The use of a Miswak.
24. Sitting in the company of the ‘Ulama (Scholars).
25. Sitting in the company of the Pious.
26. Abandoning futile talk.
References for the above:
Al-Faqih wal Mutafaqqih, vol.1 pg.103, Al-Jami’u li akhlaqir rawi, pgs. 400-406, Muqaddimah ibn salah, pg. 247, Sunan Darimi, vol.1 pg. 155-158, Al-Hath ‘ala talabil ‘ilm of ‘Askari, pg. 73, Ta’limul Muta’allim, pg.41, At-Tibbun Nabawy of Abu Nu’aim, pg.210, and Zadul Ma’ad, vol.4 pg.376
Deeds or foods that weaken the memory
2. Sour Apples.
4. All those things that cause phlegm.
5. Moist coriander.
6. Salted meat.
7. Hot bread.
8. Eating from a pot.
9. The leftover drink of a rat.
10. Reading tombstones.
11. Witnessing a crucifixion.
12. Looking at stagnant water.
13. Looking at one’s own private parts.
14. Looking at the private parts of a woman.
16. For a person in need of a Fard bath to look at the sky.
17. Looking into the mirror of a cupper (one who does cupping).
18. Using a broken comb.
19. Urinating in stagnant water.
20. Urinating on the side of the road.
21. Urinating under a fruit tree.
22. Urinating into ash.
23. Making wudu in an impure place.
24. Wiping the hands or face with the tail of the clothing/kurta/qamis etc.
25. Entering the Masjid with the left foot or leaving with the right.
26. Dusting clothes in the Masjid.
27. Sweeping with a cloth.
28. Using a pants or turban as a pillow.
29. Excessive joking.
30. Laughing in the graveyard.
31. Excessive worries of the world.
32. Cupping on the nape.
33. Throwing of live lice.
References for the above
Al-Mu’jamul Kabir of Tabarani, Kitabul ‘ilm of Ibn Abi Khaithamah, pg.31, Al-Jami’u li akhlaqir rawi, pgs.400 and 404, Ta’limul Muta’allim pg. 43, Al-Maqasidul Hasanah pg. 519, Tazhkiratu Sami’ Wal Mutakallim pg. 77, At-tibb of Imam Dhahabi, pgs.174-175 and Raddul Muhtar.
The best times and places for memorizing
Khatib Al-Baghdadi (rahimahullah) has mentioned the following in his book: “Al-Faqih wal-Mutafaqqih”
“The best time for memorizing is the time of sehri (early dawn), thereafter the time of mid-day.
The mornings are better for memorizing than the evenings, and on the whole the night is better than the day.”
He further states: “And the best of places for memorizing are those rooms which are above ground level and all such places where there are no distractions.
It is better that one abstains from places of greenery, riverbanks and the road side because such places naturally distract the mind.
References for the above
Al-Faqih wal-Mutafaqqih, pgs. 103 – 104. Also refer to : ” Qimatuz zaman ‘indal-‘Ulama of Sheikh ‘Abdul Fattah Abu Ghuddah (rahimahullah) pgs. 100-105 and Wafayatul A’yan, vol.2 pg.245.
Note: Majority of the above are mainly based on the experiences and advices of the ‘Ulama and are not from the Quran or Hadith. Therefore, one should not regard them as such.
Caution: Some the foods mentioned above may agree with certain individuals and not others. Please consult reliable herbalists.
And Allah Ta’ala Knows best.
Also see here.