Bismillahir Rahmanir Rahim.
Hadtih
1446. Hudhaifah and Abu Dharr (May Allah be pleased with him) reported: Whenever the Messenger of Allah (sal Allahu alaihi wa sallam) went to bed, he would supplicate: "Bismika-Allahumma amut wa ahya (With Your Name, O Allah, I die and return to life)''; and when he woke up, he would supplicate thus: "Al-hamdu lillahilladhi ahyana ba`da ma amatana, wa ilaihin-nushur (All praise belongs to Allah Who has restored us back to life after causing us to die; and to Him shall we return).''
[Al-Bukhari].
Commentary: The greatest benefit of such Du`a is that one always remembers Allah and keeps Him all the time in mind. What better way than to the start the day immediately with the praise of Allah, and to end the day with our last words, before going to sleep, also being the praise of Allah? These du'as are so small, make it a habit it memorize them! :)