Sadr-ush-Shari’ah, Badr-ut-Tareeqah, ‘Allamah Maulana Mufti Muhammad Amjad ‘Ali A’zami عَـلَيْهِ رَحْـمَةُ الـلّٰـهِ الۡـقَـوِی says, ‘This is probably for those who remain awake at night offering Salah, doing Zikr of Allah عَزَّوَجَلَّ, or reading and studying religious books, so that the tiredness caused by staying awake at night can be removed by the midday nap.’ (Bahar-e-Shari’at, vol. 16, pp. 79)

5. It is Makruh [disliked] to sleep in the beginning of the day or between Maghrib and ‘Isha. (Fatawa ‘Aalamgiri, vol. 5, pp. 376)

6. To sleep in the state of purity is Mustahab.

7. First sleep on your right side facing Qiblah with your right hand under the right cheek for some duration, and then on your left side. (Fatawa ‘Aalamgiri, vol. 5, pp. 376)

8. Remember the grave as you go to sleep, as in the grave we will be alone and there will be no one but our deeds.

9. When going to sleep, busy yourself with the remembrance of Allah عَزَّوَجَلَّ. Keep reciting Tahleel, Tasbih and Tahmeed (i.e. keep reciting (لَاۤ اِلٰہَ اِلَّا اللّٰہُ), (سُبْحٰنَ اللّٰہِ) and (اَلْحَمْدُ لِلّٰہِ)) until you fall asleep because a person wakes up in the same state that he falls asleep in, and on the Day of Judgement a person will rise in the same state that he dies in.

(Fatawa ‘Aalamgiri, vol. 5, pp. 376)

10. Recite this Du’a upon waking up:

اَلْحَمْدُ لِلّٰہِ  الَّذِیْۤ  اَحْیَانَا  بَعْدَ  مَاۤ   اَمَاتَنَا  وَ اِلَیْہِ  النُّشُوْرُ

All praise is to Allah عَزَّوَجَلَّ who gave us life after death and to Him we will return.

(Sahih Bukhari, vol. 4, pp. 196, Hadees 6325)