Gazamo's Tips n Tricks are cool. I use to watch them but now I don't. I reckon going to PMC and getting a lot of inspiration from the builds by people that are high level.
The biggest thing Im missing on these pictures, are the two cave systems I spent a lot of time building. One's in the floating island, which also provides a way to get down to the main land without flying, /jumping or falling (to your death ) and on the 'mainland', in the hole the island left behind, on the same spots where the caves from the floating island would've been, there're 2 entrances to another (way bigger) cave system, that you can get lost is very easily. There's also a library in there somewhere, which I tried to make like a stronghold library. I am planning on making a nice decending path to one of those entrances, because they're quite hidden behind vines and stuff.
Ill probably make a passage between the "miner's secret" thingie in one edge of the shop, and connect it with the cave system above that.