Which way is North

When creating a map of the north pole or south pole, which direction should the north arrow point on the map?? Not a problem away from the poles, but north pointing up on a map is convention only. Many of the oldest maps were oriented such that east was pointed up. And for that matter, why is 0° Longitude based on Greenwich meridian? Many of the older USA maps show 0° Longitude through New York City. Simply put - it is convention. An agreed upon standard that all can base their starting point from. While standards are important, I'd also challenge you to think beyond standard convention. North isn't always up...