It's easier than you might think, just a year ago I was building square boxy houses. Just takes practice and a little research on building techniques, get world edit and learn to use even just the basic commands like copying and pasting, and replaceing blocks with other blocks. Circles are a great thing to learn also. A great way to get practice is to find some blueprints online and build from those, then start building your own stuff. Just be creative, I'm constantly changing things while I build if something isn't working well or I think of something new I just break out the old and redesign. I also uploaded the testing ground maps that I made and use to work on my builds, might help ya out. It's in with my other uploads, give it a try :) Best of luck to you.

WOW! That is amazing. I love Minecraft but would never be able to build something like that. Congrats! Ü