Probably 2-in-1 shampoo was the first beauty product that offered to save you a step, and for a while it was everywhere: in every gym bag, in every travel kit, on every bathroom shelf that didn’t have room for two bottles. BB cream did something similar for the face a while later, folding moisturiser, coverage and a bit of sun protection into a single tube. With time, those two became the shorthand for what a multitasking product could do, but the list is a good deal longer now. Blushes that...