On a long-haul flight, the goal is not to look as if you dressed for the airport. It is to arrive looking as if you did not spend eight hours in the air. The answer is the same in economy and first class: soft, structured layers that keep you comfortable in a cold cabin and presentable at the other end.

Dress in Layers

Cabin temperatures swing between the boarding gate, the cruise and the descent. Plan on three layers: a breathable base, a warm mid-layer and a coat or jacket that can be stowed. A fine merino or cotton-jersey top against the skin, a cashmere crewneck or cardigan over it, and a tailored coat on top means you can adjust without standing up.

Trousers With Give

Anything with a rigid waistband becomes uncomfortable after a few hours seated. Choose a tailored jogger in wool or a ponte knit, wide-leg trousers with an elasticated back, or a knitted set. They look intentional at immigration and do not crease the way linen or cotton chinos will.

The Wrap Does Everything

A large wool or cashmere scarf is the most useful thing you can carry on board. It is a blanket in a cold cabin, a pillow against the window and a finishing layer for dinner on arrival. Choose it in a neutral that works with your coat.

Shoes

Feet tend to swell on long flights, so wear shoes with some room: loafers, soft leather sneakers or slip-on boots. Avoid laces that need retying and anything new. Many travelers wear compression socks on long flights; if you have any circulation concerns, ask your doctor what is right for you.

Keep It in the Carry-On

• A clean top and fresh underthings, so you can change before landing.
• A toothbrush, a small moisturizer and lip balm. The cabin air is very dry.
• Eye mask, earplugs or noise-cancelling headphones.
• An empty water bottle to fill after security.
• Any medication you need, never in checked luggage.

Before You Land

About an hour out, change your top, brush your teeth, put on moisturizer and fold the wrap over your arm. Arriving rested is mostly sleep. Arriving put-together is the ten minutes before the seat-belt sign comes on.