comma after speech tag [mandatory?] ...," I said, surprised at his

English - Australian
After dialogue, is it correct grammar to always use a comma after the 'said', as in the examples below, or is it more appropriate to leave it out? For example, I said with a smirk doesnt pause so it sounds better without a comma.

… ,” I said, surprised at his question.
… ,” Darrell said, as Brandy dragged me away
… ,” I said, glancing at Mrs. Mathews.
… ,” I said, laughing.
… ,” I said, with a smirk.
… ,” Mr. Johnson said, but I wondered if he was serious.
… ,” I said, while trying to contain my surprise.
  • The comma is not really after "I said", it is a comma setting off the non-essential clause that ends the sentence.
    It is an example of the bracketing comma described HERE.