I think we can take it further. A true 3D experience adds a third dimension, up and down.
Readily accessible are well made 3D chess boards. Basically, they are usually 3 chess boards built to stand over each other. There are variations on this that add more boards, but the standard is 3. By using such a set of boards we can simulate height. Simulating height has always been difficult, but 3D chess boards can do this easily. Adding a second set of boards can expand the playing area over a wider area.
This can be used in any encounters wherein the characters are flying or swimming. Just add a rule where moving or attacking from one board to another adds a range of 10'.
This setup can also be used in unique encounters wherein the terrain has special teleportation circles that moves them from board to board. The encounter becomes one of tactical teleporting as the characters try to outmanuever the monsters.
Another option is to prepare an entire setting such as a tower or dungeon wing. You can lay out the entire dungeon ahead of time. While the players will be able to see the props in place ahead of time, it will save the DM alot of time. Instead of drawing rooms and erasing them, or slowing down narration as he places the next rooms props, it can be done ahead of time. Seeing what rooms are coming up can also build anticipation with the players.
Another option is to prepare an entire setting such as a tower or dungeon wing. You can lay out the entire dungeon ahead of time. While the players will be able to see the props in place ahead of time, it will save the DM alot of time. Instead of drawing rooms and erasing them, or slowing down narration as he places the next rooms props, it can be done ahead of time. Seeing what rooms are coming up can also build anticipation with the players.
If you try any of this out, let me know how it went.