Prepare your documents before you reach the queue

Security rarely goes wrong because of the scanner. It goes wrong because someone is still hunting for a passport while their tray slides out of reach. Sort the paperwork before you join the line and the rest becomes straightforward.

Have your boarding pass ready to scan — if it is on your phone, turn the screen brightness right up and close any other apps. Hold your passport open at the photo page, and keep anything unusual in the same place: a visa, a biometric residence permit, a letter from a hospital or a school confirming why you are carrying medication. One pocket, one wallet, no searching.

It also helps to know what your departure airport expects. Family lanes, fast-track arrangements and the way boarding passes are checked vary from terminal to terminal, and a two-minute check the night before removes all the guesswork. Treat the process as a series of small, predictable steps, because that is genuinely all it is.

Pack your liquids the night before, not in the queue

The 100ml rule is still the single biggest cause of hold-ups, so deal with it at home with the kettle on rather than at the belt with a queue behind you.

• Containers: each one must hold no more than 100ml. A 200ml bottle with only a splash left in it still counts as 200ml, and it will be removed.
• The bag: a single clear, resealable bag — roughly 20cm by 20cm and no larger than one litre. One bag per person, and it must be able to close.
• The exceptions: prescribed medicines, baby milk and food, and essential dietary products are allowed in larger amounts, but you must declare them separately rather than let them roll through unnoticed.
• Newer scanners: a growing number of UK airports now use next-generation equipment that lets liquids and laptops stay inside your bag. Rules still differ between airports and even between terminals, so check ahead rather than assume.

Decanting toiletries into travel bottles at home also saves money, weight and a great deal of irritation at the other end.

Laptops, cables and the tray routine

Large electricals usually need to come out of your bag and sit in their own tray — laptops, tablets and anything similar. Cables, chargers and headphones can usually stay packed, but they tangle and confuse the image, so keep them neatly wound in one pouch.

Power banks and spare lithium batteries must travel in the cabin, never in checked baggage, and most airlines cap them at 100 watt-hours. Tape the terminals or keep them in a protective case so they cannot short against a set of keys.

Sharp items are worth a mention too: scissors with blades under 6cm are generally permitted, but anything longer belongs in the hold. If in doubt, leave it at home.

What you wear changes everything

Dress for the scanner, not for the departure lounge. Metal is the enemy: belts, buckles, watches, bracelets, large earrings, hair clips and heavy necklaces all trigger alarms. Slip them into your hand luggage before you reach the tray rather than fishing for them afterwards.

Choose shoes you can remove without sitting down, and avoid boots with metal shanks — several airports ask for footwear to come off regardless. A jacket with zips is fine; a jacket with a dozen pockets is a nuisance, because everything inside it has to come out. Coins, keys and loose change go in the bag, not in your pocket, and an empty pocket is a fast pocket.

If you wear a medical device, carry a card or letter explaining it, and mention it to the officer before you step through.

At the scanner: calm, clear, cooperative

Step forward only when you are invited, and take your time — nobody is timing you. Place one item per tray where you can, and push the tray forward rather than letting it bunch up.

If you are asked to go through a body scanner, you can request a private search instead, and a pat-down can be carried out by an officer of the same gender. Say so politely and it will be arranged. If you are travelling with children, with a disability or with a hidden condition, tell staff early — most airports have a discreet lane or a quiet route that makes the whole thing far easier.

Above all, listen. The instructions are short, they are repeated constantly, and following them is the quickest route to the other side.

After the belt: regroup and relax

Collect your belongings on the far side, count your trays, and step away from the belt before repacking — standing at the end of the roller is the one thing that slows everyone else down.

Then put your belt back on, pocket your passport, and take a breath. You have cleared the most stressful ten minutes of the journey, and everything from here is a matter of finding your gate.