If you use Markdown you know that you can make text bold by surrounding it with double underscores or double asterisks. Using italics works the same way, but you surround your text with single underscores or single asterisks.

In my job I frequently review text created by someone else, and need to select portions of the text to mark as bold using Markdown. I perform this action quickly with a keyboard shortcut that triggers a simple Keyboard Maestro macro.1

Here’s what the macro looks like:

All the macro does is take the selected text, adds it to the clipboard, and then repastes the clipboard contents, surrounded by the Markdown syntax, in place of the original text. To get italics instead of bold, you’d change the third step to use a single underscore instead of the double underscore depicted in the image above.2

Here’s the macro to download (you’ll need to unzip it after downloading it):

Keyboard Maestro Markdown Bold Macro