In professional typography, you use curly double-quotes for your quotation marks — not straight quotes, that’s a relic from the age of the typewriter.
This is a straight double opening & closing quotation mark
This is a curly double opening & closing quotation mark:
So the following is bad typography:
This is good typography:
To make double quotes on a Mac keyboard, instead of holding down Shift + 2 as you do for straight double quotes (both opening & closing), you hold down Alt/Option + 2 for the opening curly double quote (
“), and Alt/Option + Shift + 2 for the closing curly double quote (