The most significant rule of thumb, around my mind, requires you to keep burning candles out of the children and pets.
Each year you should check all of the lights and wiring for shorts various other malfunctions before placing them on the tree. https://Getreallive.com/2025/05/30/la-importancia-del-vidrio-resistente-al-fuego-en-la-cimentacion-moderna-en-el-ambito-de-la-edificio-y-la-construccion-modernas-la-seguridad-es-primordial/