The first thing I work on when I start an image is to get the whole visual concept right. I start with sketching: just rough linework to figure out where everything goes. I need to find the optimum angle for viewing the elements in the image, and to figure out which areas should be detailed and which should be clean.
This image is all about presenting a new-world, futuristic vision: everything is white and bright. From the start I planned to use plastics and other shiny materials: anything glossy is just a dream for a 3D scene, but I had to be careful not to overdo it. There are other, less obvious ways of generating an otherworldly feel. The light here is intentionally really clean, with just a hint of artificial lighting. The aim is to achieve a sensation of high altitude, a feeling of being above the clouds.
I've used a mixture of global illumination (GI) and area lights rather than only GI, which is what many people would tend to do. By adding in some area lights, you get much smoother Radiosity calculations, and a finer render overall. I did one main render, which took about 20 hours, then a series of render passes to enhance certain details.
I don't often use HDRI in my renders. It has a tendency to control the image, to dictate the feel of the lighting. Sometimes you can be creating a rod for your own back. I prefer to find a point between what people want to see and what a camera would actually capture.
A lot of my work is conventional photography, particularly advertising shoots. I've long applied my experience there into building and lighting virtual studios for my scenes. But I also strive to create a photographic feel through my modelling and rendering decisions. Understanding photography gives you a real insight into how light works in the real world.