It's important to avoid Theme Park World though. A common trend in LOTC maps is to have flat grassy plains as the default, and then they go through a shopping list of biomes, adding them to different corners of the map. It makes all the untouched (or barely touched) parts of the map extremely dull, while the few biomes there are are then exaggerated. Every mountain has to be unscalable, every forest has to have gigantic trees that block out the sun entirely, etc.
The map leak was pretty worrying because it looked like every mountain was part of a gigantic range designed to separate nations from each other (why???), all the interesting biomes were shoved to the corners of the map, the snowy part was a clear wasteland, etc.
A greater number of less drastic biomes and terrain features would be in order IMO.