Before you even leave home, check with your mobile provider that your SIM card offers a roaming service (that is, it'll work when you try to use it in a foreign country). Most SIM cards nowadays are automatically set up for roaming, or can be easily activated, but some pay-as-you-go accounts won't allow it.

A dual-band handset can be used throughout the UK and Europe, but if you're travelling to North America, you'll need a tri-band handset. In certain countries, such as Japan and Korea, you'll need a handset with a 3G connection.

While most providers will allow you to use your mobile abroad, it is quite a bit more expensive than using it at home. This is because your mobile provider has to pay a foreign network to host your calls, texts and internet. Make sure you check what the rates are for roaming use before you leave home - that way you can gauge how much usage you can afford.

As convenient as it is to have the internet on your phone while you're travelling (both for staying in touch with the folks at home, and researching destinations on the go), this is probably the most expensive of the roaming services you can use. Hence, you may find it's more cost-effective simply to switch off the internet option on your phone for the duration of your holiday.

If you're going on an extended holiday to a single destination, or holiday regularly in the same place, it may be worth picking up a SIM card from a local mobile company. That way you can make local calls and texts at a much more reasonable rate.

If you're planning to make calls home, or to other international destinations, it may be wise to get an international SIM card that offers cheap calls to other countries, such as that offered by Lebara in the UK. The rates offered on these SIMs are comparable to those of calling cards, but they're less complicated to use and won't expire or run out at inconvenient times.

Something to keep in mind when assessing the cost of using your mobile abroad is that most operators will charge you for receiving, as well as making calls. Some will even charge you each time someone leaves you a voicemail. If your operator does not charge when you're left a voicemail, you might be better off setting up all your calls to divert to voicemail - that way, you can just reply to the important ones, rather than getting charged every time some well-meaning soul just wants to say hi.

If you have a pay-as-you-go account, make sure your phone has plenty of credit before you leave - it may not be easy to top up with your particular mobile provider once you're abroad. If your account has the option, you may want to consider automatic or scheduled top ups, to reduce the risk of running out of credit midway through your travels.

Having a phone set up for roaming is no good if it runs out of battery charge the first day of your holiday. Make sure that your phone charger is compatible with the voltage and outlet configuration in your chosen destination, and if not, pick up any necessary converters or adaptors before you leave home.

There's always a risk your phone could be lost, stolen or damaged while on holiday, so you should look into insurance options before you go. If your current phone insurance doesn't cover international use, check that your travel insurance policy covers gadgets like mobile phones, and be clear on the terms and procedures for making a claim.