Shampoo does most of its work on your scalp. The lengths tend to come clean on their own, from the lather rinsing down, as long as you rinse well. If you've been working shampoo all the way to the ends, you can ease off that. It usually just leaves them a little dry.

It helps to wash twice. The first time mainly loosens the oil and the day's residue. The second is the one that actually clears it away. If your roots feel heavy, or it's been a long day, a third or fourth pass is fine.

Use the pads of your fingers, and keep your nails off the skin. Press gently but firmly. Your scalp can take a bit of pressure, as long as you keep it slow. Nails tend to leave small scratches that can feel sore the next day. If your hands get tired, a soft scalp brush does the same job.

There's a helpful step before you even start: give your dry hair a good brush first, around eight minutes. Wet hair tangles and snaps more easily, and a knotted head is harder to clean. Brushing also clears the hairs that have already shed, so they don't wind around your fingers or block the drain. If you can, let the scalp settle for ten or twenty minutes afterwards. If not, brushing the night before works just as well.

One gentle note. If your scalp is irritated or you are shedding more than usual, skip the firm brushing and the massage for now.

When you're done, ease the water out instead of wringing it. Blot with a silk or microfibre towel, without twisting. Then a mask or conditioner through the lengths, and a leave-in to finish.

It's a small change, but a clean scalp is what most of it comes down to.