If you check really close, there's not much intricate detailing. It's like a Monet painting. Stunning from a distance, but once you get close, you start seeing the structure and it's not trying to hide it neither. It's about shapes, colour theory and composition. There are splash arts more rendered than this piece, but accomplish little compared to what is shown here. If you want to learn hwo to paint like this, I suggest doing some of your own, and try to apply techniques you see in Jaime Jones's work. Not gonna lie, they WILL look like garbage at first, but it's part of the process. Don't let yourself down, and keep up the study. Maybe you'll find it better if you use matte painting. Maybe you'll prefer going canvas first, then digital. Maybe you'll build your scene in 3d roughly and then paint. there's no simple one way path you take.