Bismil-laahi rrahmaani rrahiim.
Kul a'uthu bi rabbi n-naas. Maalikin-naas. Ilaahi n-naas. Min sharil-vasvaasil-hannaas. Allathi yuvasvisu fii suduurin-naas. Minal-djinnati van-nas.
"Say: "I search the shelter of the Lord of Mankind, the King of Mankind, the God of Mankind from the Dajjal evil disappearing [at mention of Allah] exposing temptation at people hearts, [presenting] jinns or people" (see Quran, 114).
Every night before going to bed the Prophet Muhammad, let Allah bless and greet him, blew at the palms and then read three last surahs of Quran (Al-Mu'avvizat) - "Al-Ikhlas", "Al-Falaq" and "An-Nas". Then he rubbed the body with his hands three times beginning with the head and face1. As said in one of the Hadiths of the Prophet Muhammad, let Allah bless and greet him, the man having voiced and done everything above mentioned, is to be protected from any bad upto the morning. Also before going to bed it is useful to read the ayat "Al-Kursi".
1 See, for example: Al-Bukhari M. Sahih al-Bukhari (Summary) [Hadiths corpus of imam al-Bukhari]: In 2 Vol., V.2, p.260, Hadith #1443(5017).