Map projection... the artistic side
Many sites tell you what a map projection is and how they are done, but how do projections and orientations affect map design?
Briefly, map projection is the study of translating the three-dimensional earth onto a two-dimensional map.
Projection doesn't really affect small area maps that have little distortion from flattening...
But they can highly influence the appearance of contenental or world maps.
The map projection you choose can also include a piece beyond "correct". It can include the decorative side.
For example, the interupted sinusoidal projection can be decorative by itself. It can be further decorated by adding features in the interuptions.
There are many ways to use projections for decorative effect.
The most obvious way of enhancing a unique projection is by including rhumb lines, which are lines indicating bearing. Unique projections create unique rhumb lines that can wave or direct attention to a particular point on the map.
Map orientation
Map orientation is simply the compass direction pointed up. Modern mapping conventions use north as up. But the north-up mapping convention hasn't always been the case...