Im actually doing this myself. I wanted to be able to see the village from my house but there was no where decent to build so I chose the mountain. I havent gotten even close to finishing it yet but I thought this might spark some ideas for you.
I swapped to creative to take those for you. My mountain kinda had a weird point coming out and I thought it was a good idea to make it like a diving board into the water for a quick exit to the village. I want to do a second floor under the first that's bigger the same way since I kinda started towards the top of the mountain. My biggest issue is I cant decide what to do for my walls since nothing goes good with my floors and ceiling.
I'm also going to cover where you can see things that make it look less natural I just haven't gotten to it yet.