In social etiquette, what taboos should be avoided when laughing?

When smiling in formal occasions, you should refrain from the following behaviors and performances: (1) Fake smile: Fake smile, that is, a fake smile, a fake smile but no real smile. It goes against the principle of authenticity of laughter and is worthless. (2) Sneer: A sneer is a smile that contains anger, sarcasm, dissatisfaction, helplessness, disdain, disapproval, etc. This kind of smile can easily make people hostile. (3) Weird laughter: Weird laughter, that is, laughter that makes people feel numb. It often contains intimidation and ridicule, which is very offensive. (4) Charming smile: Charming smile is a smile that is intended to please others. It does not come from the heart, but comes from a certain utilitarian purpose. (5) Laughter: Laughter is shyness or stage fright. For example, when laughing, they cover their mouths with their palms, are afraid to exchange eyes with others, and may even blush and speak incoherently. (6) Snickering: Snickering means laughing secretly. It mostly expresses complacency, gloating or looking at other people's jokes. (7) Smiling: Smiling, that is, looking evil when laughing. It mostly expresses anger, fear, and scaring others. There is nothing aesthetic about this kind of smile.