Add Command-I to your list of essential Mac keyboard shortcuts. It turns selected text into italics. If it's already italicized, it turns italics off.
How to find stuff on the Mac’s Desktop
Quickly find items on your desktop (or in any Finder window) by typing the first letter of the item. You don't have to search. Just type.
Essential Mac Keyboard Shortcuts: ⌘-B for Bold
Command-B toggles "Bold" on and off. This is one you have to know: I rate it up there with Command-Z, -X, -C, and -V. And -P.