A style does not survive the night intact, and it is not meant to. The job on the second day is to bring the shape back using what is already sitting on your hair.

Start by doing nothing. Take out the tie or the clip and give your hair ten minutes to itself. It will fall part of the way back into shape on its own, and there will be less to do than there appears to be in the first minute in front of the mirror.

Then water, and very little of it. A light mist, or damp palms drawn down the lengths, is enough. Water softens what you put on yesterday, and sections start gathering to each other again the way they did on wash day. Half the time it settles the whole thing on its own.

Add product only where it is needed. If the crown is frizzing, work on the crown rather than the whole head. A second layer over yesterday's weighs hair down faster than it freshens it, so reach for something light and less of it than you want to use.

Then dry it — a diffuser on a low setting, or plain air — and keep your hands off it until it is dry. Hair sets in whatever position it dries in, and every touch on the way breaks up what you have arranged. It is the same rule as on wash day, and people break it more often on the second.

Once it is dry, work the stiff parts loose between your palms. If the roots look heavy, dry shampoo takes some of the oil off and gives the lift back, though it works as support rather than as a replacement for washing.