Shift-Option-K — type’ the Apple symbol
Below are the Unicode hex numbers for the most common symbols used to represent Mac control keys. You can type these by finding the numbers in the Character Palette or similar font inspector program, or by using the Unicode Hex Keyboard (key in Option plus the number). Lucida Grande is a good font to use.
Apple/Command: 2318 ⌘
Alt/Option: 2325 ⌥
Shift: 21E7 ⇧
Delete: 232B ⌫
Control: 2303 ⌃
Apple Logo: F8FF or Option-Shift-K