Floating Island Look

I want to give my terrain the look of a chunk of land floating in a sea of Aether, but so far i can not come up with a convincing way to do this. Anyone have any ideas?
I thought of using a Skybox and rock assets around the terrain, but so far the look isn't satisfactory.

 

For a floating island, I think it's important to make clear its an 'island' more than it is floating. Any floating islands I've seen so far reminds me of a jellyfish at the surface of the sea. What I mean by this, we don't know about floating islands (cause there aren't plenty of examples to see), so you have to make it very clear to understand.

For a project I created a floating island once and used artificial structures and natural ones to define the top and bottom of the island:

The hanging plants showing that there is gravity and a 'way down'. A tower at the top shows that it has a solid surface one can move on. The shape (more high than wide) makes clear that it is a thing that must float, cause it couldn't be stable else.

Also I showed that there is a possibility to fall down right from the beginning.

With that, there should be no doubt what is going on in this scene...

 

Thanks for the tutorial! Keep'em coming!