This will be a significant expense for your trip. As a general rule, the more slowly you travel, the less it costs. Booking as far in advance as possible is another way to cut down those costs. Travelling with the locals is also a sure way to save money - and a sure way to get an 'authentic' cultural experience (for better or worse). However, sometimes using local transport can take significantly longer and be far more uncomfortable, so you'll need to take it on a case-by-case basis.
During the planning stages, think about which countries you're travelling to and whether or not you can travel between them overland or if you're going to fly. Put approximate costs and travel times together and your journey will start to take shape.
During our overland trip from the UK to Australia, we travelled every which way: by car, train, bus, mini van, plane, boat... Below are some of the tips and tricks we picked up along the way.
When it comes to planning and booking your flights, Skyscanner is your friend. It's a great tool for finding and selecting the best deals on flights from anywhere to anywhere. The earlier you book, the better/cheaper.
Keep in mind that ticket prices are often dependent on where you are when you make the booking. Hence, it may be worth booking some of your flights during the journey, rather than before you leave.
We love train travel. In most countries, it's reasonably priced as it's used regularly by the locals; sleepers can help you save money on accommodation and allow you to sleep through long journeys; unlike some other ground transport, they run to a schedule; and they usually arrive in the centre of town - train stations often act as transport hubs, so onward travel is simple. It's also a good opportunity to mix with the locals and to sample the local fare.
You can often book ahead online, or if you are in the country, simply visit a railway station and book your tickets as you need them.
In much of Asia, the sleeper carriages have a hot water urn at one end, so you can save money by buying pot noodles, cuppa soups and tea bags before you leave.
When it came to planning and booking our train journeys from the UK to Saigon, we found The Man in Seat Sixty-One to be particularly useful.
Some country-specific items to note:
Germany (and other European countries)
We bought our European train tickets on bahn.com. We found that they were much cheaper on this site than they would have been if we had bought them in the UK or from each country along the way. The purchasing process is simple and efficient, as you might expect from a German site.
China and Mongolia
Children's fares are determined according to height, not age. Full fare is paid once a child is taller than 150cm.
Domestic train tickets can be booked through www.travelchinaguide.com. International train tickets can be booked through www.chinatripadvisor.com. We used both of these sites and found them to be very helpful.
Actually getting hold of the tickets can prove slightly problematic. Often, they won't issue them until a few days before your scheduled departure. And in China, you will probably have to pick up your tickets from a station when you arrive. Finding the correct counter and then finding someone with enough English to sort out your tickets is part of the adventure.
Although it's possible to buy tickets for Russian trains in general, and specifically the Trans-Siberian, as you go, if you're travelling as a family and would prefer to be in the same sleeper compartment, rather than being split up into separate cabins, you're much better off using an agency to pre-book your tickets. We used Real Russia; they were very helpful and we would recommend them.
Vietnam, Thailand and Malaysia
We bought tickets ourselves by simply visiting the train station. It was simple and efficient, and we were able to choose exactly what we wanted from the options available, rather than relying on a local agent to do it all on our behalf (and then having to pay a commission).
If it's an option, travelling by car is a real luxury. We travelled for seven months around Europe in our car and it was a treat. Space is less of an issue and you can go where you want, when you want. You're much less reliant on public transport and you can be your own boss. However, it's important to check beforehand whether or not your car insurance covers you for the countries you're planning to visit (for example, in the UK, most car insurance won't cover you for driving in Albania).
Hiring or buying a car is another option, depending on where you are travelling. If you think you might want to do this, be sure to check your insurance for what it does and doesn't cover. Check your existing travel insurance or buy new insurance to cover you.
If you're planning to drive overseas, check whether you can drive on your existing drivers' license or whether you'll need an international licence.
If you buy or hire a car abroad, make sure to read the fine print. For hire cars, make sure to take photos of the car before you leave the lot. If travelling with small children, check beforehand whether your chosen hire company can provide child seats.
If you're planning to drive around Europe, keep in mind that in several countries you'll have to buy a vignette, which is a form of road tax. Prices for an annual vignette for a passenger car range from about €30 to €150, depending on the country, although some countries will allow you to buy a shorter duration version if you're transiting through.
Ferries are a fabulous way to travel, especially if you're on a driving trip. They provide a welcome change of pace and can also show you a different side to a country. We caught ferries up the Mekong River, from Vietnam to Cambodia and from Laos to Thailand, and they were among our most enjoyable journeys.
Short trips, such as the English Channel crossing or island hopping, can be a pleasant break where you can relax and watch the seagulls go by. If you're lucky, you may be able to do some bird- and/or whale-watching with your children during the journey.
We thoroughly recommend getting a cabin for longer trips. Book a four-berth cabin (many come with a bathroom) and take what you need with you on board in daypacks or shopping bags. We usually take plenty of snacks, books and activities to do on board. For evening sailings, we usually buy the ingredients for a picnic dinner from the nearest town (along with a bottle of wine) as the food on board can be of uneven quality and is often very expensive.
As with most other forms of transport, it pays to book as far in advance as possible, especially if you're planning to travel in peak season.
Don't forget that if you or your children suffer from seasickness, you need to take the relevant medication before you set sail. If your children are prone to travel sickness, err on the side of caution and give them the tablets before you board.
This is a very flexible way to travel and is usually the cheapest option. Many places now have dedicated tourist mini-vans or buses that can take you to the more visited destinations quickly and often as cost effectively as the local transport; however, they don't have anything of the local flavour about them. So, you can judge whether it's convenience or local experience that wins the day. But there's nothing quite like sitting on a small stool in the aisle of a bus because it's full or sharing your snacks with locals as you bounce through the countryside!
When we travelled overnight, we tended to do so by train, so we don't have much experience with night buses. However, from our limited experiences, and from what we've heard from other travellers, one of the biggest drawbacks is that you're often forced to travel/sleep in close proximity to strangers. Hence it pays to book ahead to ensure that your family is seated/bedded together.
In Cambodia, always travel with the Giant Ibis bus company if you can. Their service is excellent, the buses are new and clean, and safety is a high priority.
It's worth noting that in many Southeast Asian countries (for example Vietnam) it's actually illegal for foreigners to hire motorbikes and scooters if they don't hold a local driving licence. Of course, the locals and most tourists are happy to break the rules, but should anything go wrong (and given the chaotic nature of most Southeast Asian traffic, there's every chance it will), you could find yourself in trouble with the local police and/or unable to make a claim on your travel insurance.