Needs to be easy to navigate! A simple, yet clean design. I personally like smaller hubs where you dont have to walk a million blocks to get to a portal, but also depends on the size of your server. Portals should be easily labeled and if the hub is open space, make sure theres something interesting in the background like a large artpiece or some mountains. Also, clearly marked paths. Nothing worse than signs that say "___ TO THE RIGHT" and theres nothing to the right.
