Pop on something old incase you get messy.
Shampoo the hair with a PH balanced shampoo (*Cough cough* - ours is great). Without boring you with the science, these shampoos help the hair achieve the best acid balance - which in turns helps Directions develop as well as it can.
Apply Directions with the aid of a tint brush.
Comb Directions into the hair until it becomes frothy, ensuring the hair you are wanting to colour is entirely covered.