I tend to go a little overboard with links, so I took a page out of Matthew Butterick’s Practical Typography—or rather stole it—and marked them with a degree symbol:
Vigorously styled hyperlinks on a page tend to move to the foreground of a reader’s attention, like an HDTV in a hotel bar. (See also maxims of page layout.) The red circle is meant to be noticeable while you’re reading the sentence that contains the link. Otherwise it disappears, so as not to distract.
This superscript design is used for links that take you away from my site—a slight homage to the right-and-up arrow. Internal links are then marked in bold,1 which means emphasis is left to italics (thankfully Concourse has true ones).
This is something I picked up from Reeder. ↩