One of the Sunnah practices before sleep is to recite “Bismillah” and switch off or turn off fires, lights, etc. This is as per Hadith in Bukhari.
Next, dust the bed three times with your hands. This is also a Sunnah practice according to Hadith in Bukhari.
Also, part of the Sunnah is to brush your teeth and perform your Wudu (ablution) before sleep.
Furthermore, Hadith in Bukhari advises sleeping on the right side, facing the Qibla, with the right hand underneath the head like a pillow and with the knees slightly bent.
Don’t forget to recite the Du’a before sleep. It is also good to recite Ayatul Kursi and the last two verses of Surah Al-Baqarah.
These simple preparations are easy to follow. May you have the opportunity to perform all these Sunnah practices. Insha’Allah.