This part from our Eagle library is a favorite. We use the 74xx245 buffer as a 5v to 3.3V level translator in many of our projects. Many of those projects went through a few revisions, ’cause we keep getting the directional control pin wrong.
Eventually we branded a legend for the “DIR” pin directly on the schematic symbol. It’s gonna smack your face if you even think about connecting it the wrong way!
Got cool schematic symbols you’d like to share? Leave a link, or talk about them in the comments.