No commas with mildly parenthetical elements

Although you should use commas to set off most parenthetical expressions, do not use them to set off elements that are only mildly parenthetical.

Example sentence with editing. Original sentence: Charisse believes that the Internet is, essentially, one giant billboard. Revised sentence: Charisse believes that the Internet is essentially one giant billboard.

Exercises:

Misuses of the comma 1

Misuses of the comma 2

Related topic:

Commas with parenthetical expressions