Yes, there is an etiquette to be followed at the blackjack table. One of those rules of etiquette is to not tell other players how to play. Another is to not spill your drink. Standard etiquette like "please" and "thank you" still apply.

There are no etiquette rules for which plays you should make at the table, and your actions have no effect on anyone else's outcomes. Blackjack isn't really a team sport. (Unless you're on a card counting team.)