Do you plagiarise someone's design from reddit?
Do you spend time in single player creative and mock it up first?
Look at photos of real buildings and attempt to re-create them?
Just start building and see what happens?
Or do you even just dig a hole and add some cobblestone stairs... if you get around to it?
Me? I use Microsoft paint. With gridlines turned on. And at 800% zoom.
Pixel by pixel.
But only for the floor plan and some side views. Decorations, materials, and the gardening is done in game, on-the-fly.
In the Serenity modpack, I also use microblocks to make minor alterations to some of the shapes, but due to their interaction with water for example, some curves I can't 'smooth out' as much as I'd like to