Unlike the simple death stick — light it, inhale it, try not to choke up a lung cos the cool kids who peer-pressured you into sparking up will laugh — the e-cigarette is a more complicated adventure. There are disposable ones — the cheapest and most popular option; refillable ones that contain a liquid, sometimes flavoured; and advanced models for the committed nerd where you can fiddle with voltage and power consumption. Many users start at the disposable end and end up developing a connoisseur’s interest in flavours, something that, admittedly, can’t be said for the humble fag.