We used Rust-Oleum Gun Metal Metallic spray paint and chose a chevron design for our door, but you can achieve the same effect with any Rust-Oleum brush or spray product.
Remove door and repaint with your chosen base colour if necessary. Leave this to filly dry.
Move the door to a well-ventilated space and place on top of a large dustsheet or some old newspapers. You may want to cover the surrounding area with additional dust sheets/ newspaper to protect from spray mist. Wipe door clean with a damp sponge or cloth and allow this to dry before proceeding to the next step.
Using masking tape, mark out your chevrons or chosen design and cover sections you do not wish to paint with newspaper or plastic bags.
Take your can of Rust-Oleum Gun Metal Metallic and shake thoroughly. Hold the can approximately 30cm from the surface of the door and spray in a steady back and forth motion, slightly overlapping with each stroke. For best results whilst spraying keep the can the same distance from the surface and keep the can in motion. Apply several light coats a few minutes apart. Leave to dry in a well ventilated place for 24 hours.