The user places two shuriken together and throws them both at a target simultaneously; the larger the shuriken that are thrown, the greater the necessary skill. The goal is for targets to focus their attention on whichever of the two shuriken is on top, not noticing the second shuriken travelling below it. Ideally, targets will dodge the upper shuriken in such a way that they are left unable to dodge the second. If targets do at any point realise there's a second shuriken, the technique is rendered ineffective.
Naruto Uzumaki sometimes disguises himself or his shadow clones as shuriken, which either he or an ally will throw as part of the Shadow Shuriken Technique. That way, in the event that targets dodge both shuriken, the shadow clone will be well-positioned for an attack.