When you enter a home, say: Assalamu alaykum. When you eat, say Bismillah, eat with your right hand, and from what is in front of you. That is the Prophet's ﷺ manners.
A Muslim does not lie, even as a joke. If you make a mistake, apologise.
Do not mock anyone, and do not cheat in games. Return what you borrow, even a toy.
Before sleep: Ayat al-Kursi, Qul Huwa Allahu Ahad, and the Mu'awwidhat, as the Prophet ﷺ taught.