Sunnah before sleeping
1.Perform Ablution as you would for Prayer .(Bukhari Book 4 Hadith 114)
2.Perform witr Prayer if you are not waking for tahajjud witr can be 1,3,5 rakaah or any odd number (Muslim 755)
3. Dust off your bed 3 times and mention Allah’s name and say
بِاسمِكَ رَبِّي وَضَعْتُ جَنْبي ، وَبِكَ أرْفَعُهُ ، إنْ أَمْسَكْتَ نَفْسِي فَارْحَمْهَا ، وَإنْ أَرْسَلْتَهَا ، فاحْفَظْهَا بِمَا تَحْفَظُ بِهِ عِبَادَكَ الصَّالِحِينَ
Bismika Rabbi wadha’tu janbi, wa bika arfa’uhu, in amsakta nafsi farhamha, wa in arsaltaha fahfazha bima tahfazu bihi ‘ibadakas-saliheen’.