Battle and soccer arenas are actually an extension of the track format and thus most of the instructions in this guide apply to arena creation. In fact, the process of making tracks and arenas diverge only at a few points, which this article aims to cover.
Naturally, an arena is not a road circuit like a track. Arenas are a large area that contains the players and provides the features needed for battle or soccer mode. The playground area of an arena therefore needs to be more interesting and interactive than a track. Use ramps, obstacles, tunnels, and ridges to make an arena more dynamic and interesting. An arena like this is a bit dull: