Sleep with wudu
مَنْ بَاتَ طَاهِرًا بَاتَ فِي شِعَارِهِ مَلَكٌ لَا يَسْتَيْقِظُ سَاعَةً مِنَ اللَّيْلِ إِلَّا قَالَ الْمَلَكُ: اللَّهُمَّ اغْفِرْ لِعَبْدِكَ فُلَانٍ فَإِنَّهُ بَاتَ طَاهِرًا
Man bata tahiran bata fi shi'arihi malakun la yastayqidhu sa'atan mina-l-layli illa qala-l-malak: Allahumma-ghfir li-abdika fulanin fa-innahu bata tahiran.
"Whoever sleeps in a state of purity, an angel spends the night in his garment. Whenever he stirs at night, the angel says: O Allah, forgive Your servant So-and-so, for he went to sleep pure."
Narrated by Abdullah ibn Umar. Sahih Ibn Hibban 1051
A short reflection
Two minutes of wudu before bed. An angel at your shoulder all night, asking forgiveness for you every time you turn. A trade with no human equivalent.