Here are two pictures; the first one is the village I made (house, well and blacksmith thing copied of generated villages)
and the second is the castle and the tower I made with some pixel art in the background. The bottom of the tower is basically a transport roller coaster sort of thing.
single player is for testing new mods, updated items, trying out new build ideas without having to go and gather all the materials first, creating large scale detailed and interesting builds without some 12yo kid burning it to the ground, stealing your stuff and then bragging about destroying over a month's work (happened to me on a vanilla server, I built a 200x200 chunk town and it was torched over a few days while I was away working and a forum post with before and after pics) it is also good for trying out redstone contraptions without having to worry about space or material limits, and yes for PEOPLE (NOT NOOBS) who don't want to get killed by people who enjoy ruining an exploration session (valid reason, doesn't make you a noob to not want all your stuff stolen when you're 1000+ blocks from your bed)
These relate to an underwater library.
Underwater hallway idea.
Haunted house building, lost pictures of interior though.
Floating island(s), the first one I've ever build, a few years back in survival.
A hallway of a dungeon that I call, the Infernum, I had a Wikipedia written with full back story.. Lost that also.
Overall, I've improved with how to build for the most part I'd say.. seeing myself as a sci-fi building for the majority, but I can build fantasy, medieval.. etc.
Future notice: sorry if in wrong section of forums.