Unless your hair is Rapunzel-like, a R2-coinsized drop of conditioner is plenty for most hair types and lengths. On fine or short hair, work it through the ends only; on thick hair, spread it from ear level down. ‘Leave it on for at least one full minute before washing it out,’ says dermatologist Dr Francesca Fusco. When applying a deep treatment, which Fusco recommends doing once a week, scoop out a R5coin-sized blob (for short hair, use half of that) and finger-comb it through strands, avoiding roots. ‘Put on a shower cap to enhance absorption of the mask and let it sink in for at least five minutes,’ Fusco says.