A Deeper Look at Making the Planes

A Homebrew version of the Planes

In the world of Emia, there are some very different origins for the planes, the world beyond our own, the planes and the void beyond. The Inner Space, is the world we all understand, where Earth and the galaxies and stars exist. Emia, and a land called Tarneris, also exist in this same space, but overlap each other in a dimension that exists in the same space but not in the same time. If you wanted to reach Emia from Earth, you couldn't warp anywhere in Inner Space to find it without some kind of temporal flux through a black hole, and there's currently no fixed means to do so. Those who have attempted have either never been seen or heard from again, or perished in the attempt.
The Darklands and Seelielands are the host of all manner of odd creatures, both that of elves, faeries, monsters and other vermin. They often can cross over into realms using their own magics using weak points or 'portholes' where the barrier between dimensions are thin (again, accept for Earth, which has an unknown barrier that keeps these portholes at bay).
In our world, The Veil is a kind of membrane responsible for the seepage of magic energies and conjurations from the planes and is the root of all magic in the realms (that being Emia, and Tarneris). However, Earth has been shielded by a shield of unknown origin that keeps magic out, which is why we on earth cannot cast spells and must rely on the raw energy of electricity and the use of physics.
The Shard Wall, is a hard substance that often gets broken off in pieces during massive magical events and sometimes bits of it can be found on the material planes in the form of crystal shards. This layer protects the inner layers from the forces beyond, that of Dath (Hell) and Celest (Heaven) where the devils and celestials exist. But, more importantly it keeps out the creatures that roam the Abyssal plane and that horrid of horrids, the Far Realm, believed to be the fleshy origins of life itself, without order to keep it in check.
The Ether, the Void beyond has not been recorded or visited in my campaign, and I will not dare to speculate on what exists beyond all known existence.
The Deitic Gap, the space around the planes of Dath and Celest, is where the power of the deities and devils presides, and the tapping force for clerics and paladins on the material plane.
The Causation Membrane, perhaps one of the more bizarre of locations, connects directly to the Far Realm and shields the Deitic Gap with only pinpointed connections to that which makes flesh possible, the Far Realm. What it is, or it's existence even, is still a mystery to all forms of life on all the material planes.