“Like surfing through Space.” ~ Vervain Lavine
Once you understand the way the realms are held together by the Aether, you have the foundation for understanding the technique of tracing. Tracing, like the God Realm, was actually invented by the Fey. Back when Faerie was connected to Earth, the Fey taught tracing to both gods and witches alike. Witches lost the knowledge of how to trace through the centuries but gods have always needed the aetheric travel to get them back and forth between realms.
Witches began to use the Aether only for spellwork. They would project their intentions into the Aether and the magic of that place of pure thought, would help manifest their spell. Vervain is the first witch in hundreds of years to be able to trace, simply because she discovered the knowledge of how to trace within Ku’s spellbook.
At first, Vervain could only trace from one stationary tracing point to another through the use of chants. Stationary tracing points are like portals that have been built into realms to direct entry into specific territories. Once she became a goddess though, Vervain gained the ability to travel anywhere she’d been to before or knew the direct coordinates of. Basically, as long as she could direct the energy of the Aether, it could take her there.
Outside of warded zones like Faerie and the God Realm, tracing has very little restrictions as far as location goes. But within warded areas, tracing can only be done through the tracing point, essentially it’s a magic doorway and wards prevent the formation of more doorways inside a territory. This is why you don’t see gods tracing willy nilly around their homes.