You’ve found your flight, got the hotel, and so the holiday is sorted. WRONG.

With the mid-winter travel booking boom now nearly over, millions are exposed because they haven’t finished the job – risking having to overpay on extras, or even being turned back on arrival.

So I’ve five key things to do now, to save and protect you when you go…

1) Check your passport & EHICs are valid

Most passports are valid for ten years but some countries require you to have at least six months left on yours, if not you can be refused entry. So don’t delay – check both yours and your children’s now to see whether it’ll still be valid when you travel and the rules for that country.

Like Rach who heard my warning, and tweeted me: “@MartinSLewis watching/reading your tweets without too much thought for my own passport. Thankfully I had the light bulb moment to check! Dubai in May would’ve been cancelled.”

Plus, over 5.4m EHIC cards will expire this year, check your card (look at point 9) to see. To renew go to www.ehic.org.uk (don’t google it could be a site tricking you into paying a charge – if you have to pay you’re in the wrong place) or call 0300 330 1350.

2) Get your travel insurance ASAB (As Soon As you've Booked)

I can’t stress this enough. In the run up to summer, I get people asking me questions such as, "Just found I've a breast lump and treatment will be needed all summer, I’d booked to go away in three months but my airline won't refund my ticket, , what can I do?"

Well, being blunt and dispassionate, you’ve no rights. The airline seat isn’t faulty. No more than a tennis racket wouldn’t be faulty if you broke your arm and couldn’t play with it. This is what travel insurance is for – but when I ask if they’ve got it I hear, “I was going to get it before I go”.

Half the point of travel insurance is to protect you if something happens before and you can’t go on holiday. So as soon as you’ve booked your holiday, book your travel insurance too. If not, you won't be covered should anything happen beforehand, such as an illness, cancellation, death of a family member.

There are many cheap, decent value policies available online with prices from just £9 to cover a year’s holiday. Full help, and best buys, including over 65 and pre-existing conditions see www.mse.me/travelinsurance.

3) Book car hire as early as possible to slash the cost

Don’t leave it to the last minute. If you do you could pay massively over the odds – for example, walk in now, and if they’ve got spare cars, you could pay £40+/day. Yet book now for August and it can cost as little as £8/day for Tenerife and £13/day for Malaga.

To find your cheapest, use as many comparison sites as you’ve time for, including www.kayak.co.uk, www.travelsupermarket.com and www.carrentals.co.uk. Then once booked double check the details with the car firm.

I’ve heard huge successes of people getting great deals by booking in advance, like Dave, who emailed: "Booked four months ahead, got 10 days for £296 for a decent-sized car. Just before I went, checked and price had gone to £900." See www.mse.me/cheapcarhire for more.

4) Get car-hire excess insurance BEFORE you go and save up to 80%

Often when you’re at the kiosk picking up your hire car they’ll try and fear-sell you a car insurance excess policy saying: “Hey señor, you need excess insurance too - if not and there's a problem, you’ll pay €1,000." I can't tell you how often I've hired a car and wanted to intervene when I hear this happening next to me.

This insurance can cost as much as €20 a day, so to avoid it get standalone cheap excess insurance before you go for as little as £2/day. Like Glyn who tweeted me: “Thanks @MartinSLewis, I followed your guide & got a week's car hire excess insurance for £13. Rental company wanted £12 per day."

The www.moneymaxim.co.uk comparison site can find you a cheap policy. Though be aware that if you do book this way, hire firms may say “you still need to pay us”, and this is true. You’ll need to pay a deposit of €600 - €1,350 on a credit (not debit) card, from which they'll take the cost of any incidents. Yet you can then reclaim the cost on your standalone insurance policy.

5) Not booked yet? Long haul flights are cheap now

When it comes to flights, booking earliest is usually cheapest (no guarantee though), and there are a number of big airline sales on at the moment for long haul Including BA and Virgin. So if you're planning to fly in 2018, now's likely a good time to book (though if going later in the year, check all carriers on your route have released tickets for then). For short haul flights, now is less key, but early is generally good.

If you are looking in general the best way to compare is to use a couple of comparison sites, my top picks are www.kayak.co.uk (allows you to filter based on card/baggage fees), www.skyscanner.net (particularly strong coverage of budget flights) and www.momondo.co.uk (helpful insights such as cheapest airport to fly from/to).

And for hotels, once you find what you want the likes of www.trivago.co.uk and www.hotelscombined.com will check if that’s your cheapest hotel, and check www.tripadvisor.co.uk for reviews. Though there are many other clever ways to cut the cost further in www.mse.me/hotels.

And finally if you're going away for 7, 10 or 14 days to a traditional holiday destination, a package holiday often beats separate flights and hotel, so don’t forget to try travel agents.

Martin Lewis is the Founder and Chair of MoneySavingExpert.com. To join the 12 million people who get his free Money Tips weekly email, go to www.moneysavingexpert.com/latesttip.