As said in the previous Tutorial (Building Fantasy Roofs), i will be showing you how to make the Floating islands seen in some of my projects. This will require WorldEdit/SinglePlayer Commands or a Server with the requiered plugins.
This time, i downgraded to 1.5.2 so i would be able to get both W/E and shaders. The Texturepack is JohnSmith.
This is how i build all my islands and i am sure there are others who use the same method.

1. Start off by making a world with nothing. Turn Flatworld and use the preset 0x0.
2. Make a circle with the command /cyl 3 20 - 20 is the size i use most of the time and 3 is the id for Dirt

3. With the command /tree Pine, start planting trees around the floor until it is completely filled.
4. Just like a mountain, add layers of trees, each one getting smaller until only one tree can fit. You can make it point which ever way you desire, as long as it doesnt go outside of the circle's radius. Around the outside of the sphere, plant smaller trees with /tree.
5. Select the entire are with either //wand or //pos1-//pos2 and do //replace leaves,log sand. Dont just do //replace sand as the whole base will became sand and fall. This may cause a bit of lag according to the strength of your computer.
6. Do a //smooth to remove the spikes and then manually add spikes to the highest points of the island.7. Replace the whole build to stone with //replace stone.
8.As you already have the whole area selected, copy (//copy) and do a //flip down. This is, as said in the command, flipthe build down to create the floating island, as if it is just an upsidedown mountain. Now all you have to do is //paste!
9.Using the brush /brush sphere stone 5, terraform the top part of the island so it isnt flat and smooth it with /brush smooth 5.
10. Geez thats a lot of instructions/spoilers... here, have a potato :D
11.With the command //naturalize and the whole area selected, 'naturalize' the top of the island to make the island look normal (stone,3 layers dirt and 1 layer grass)
12. Using a new brush and the command /floodfill 50%ice,20%snowblock,20%stone,5%dirt,5%cobblestone 5 - (or the id of the blocks instead of the block name), paint the bottom parts of the island such as the spikes. The next layer, above the one you just made, will be /floodfill 10%ice,10%snowblock,50%stone,20%dirt,10%cobblestone 5 - anf paint the middle level of the island. Finish of with /floodfill 40%stone,40%dirt,20%cobblestone 5 - to top up the upper level.
13. According to what you are aiming to do with the island, you can add more features to it to your preferences. I usually just add water sources around the island flowing down, small ponds, rock spikes, leaves crawling down the sides and custom trees.
I Hope you enjoyed this, I may be uploading the map itself for you to look at or a seperate map with each steps 1 by 1.

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