What I tend to do is come up with awesome ideas for houses, but don't actually build anything because I can't be bothered to stare at cobblestone for hours.
I'm not really sure how I get ideas, just say "You know would be totally awesome?" and then whatever naturally occurs to you after that is a cool thing to build.
If I could be bothered to start building again, this what I would build:
I giant spherical underwater mansion, made entirely from glass.
A series of batcave style structure built inside the tips of a few mountains (in the middle of a mountain range) with bridges connecting them together, possibly made from glass.
A man made island in the middle of the sea, lit well, and so far from regular land that mobs pose no threat to me, and I cn just leave all my belongings and crafting stations underneath the shade of the torch clad trees.
A series of trees planted closely together, so that I could create a gigantic platform of leaves, and carve out my home. This is my "eco friendly, everything I do is renewable" plan.