Try It Yourself
If you have never worked with marker pens, remember, less is more. Build up your tones gradually. Add a wash of your lightest colour first, step back, then layer in mid-tones and shadows. Keep checking your work from a distance so you can see the balance of colour and contrast.
If you do not have your drawing to render, take an image from a design magazine, sketch it out with a fine liner or pencil, and start there. Begin with light tones, then layer darker colours for depth, adding texture and highlights last.
The hardest part is knowing when to stop. It is tempting to keep adding more, but sometimes the most beautiful results come from restraint, allowing the white of the page and the looseness of the lines to shine through.