One of the best things about Christmas is that it gives you an excuse to finally splash out on that one thing you've had your eye on for months.

For many, it's an upgrade on your sluggish smartphone or replacing that handset with the cracked screen.

As with any major purchase, it's really important to do your ground work to make sure that you're getting the best deal so first off, consider these points.

(All information relates to contract packages available with a new smartphone handset.)

1) Look at your usage

The best way to ensure that you're getting the right package and aren't going to end up with a big bill is to go through your past usage. How much data do you use in a month? How many minutes/texts? Who are your most used contacts and what network are they on? Log on to your mobile provider's website, access your account and you should be able to find this information in your bills.

2) Decide on your minimum requirements

You may have a specific handset in mind but if not, decide on your priorities features before you go shopping. Are you looking for something small with a sleek design? Do you need a big screen for using the internet and watching movies? Do you need a sharp camera or a fast processor? Knowing what you want will make it easier to choose between the huge amount of handsets out there and could also help you find a more affordable phone that still ticks all your boxes.

3) Know your budget

It's very easy to get pulled into buying the 'bells and whistles' latest model once you get into the shop so decide on an upper limit in advance to help resist temptation. Handsets can be free or much cheaper if you sign a lengthy contract but once you sign that dotted line, there's no going back so if you're thinking about leaving the country or could have a change in circumstances, give it some serious thought.

Ok, so you've decided on the phone, contract length and usage that you need. Here's what the main operators are offering.

02

While many providers now insist on a 24 month contract for smartphones, o2 allows you to choose whichever length you want - from six months to 24 months.

Obviously, you'll pay a lot more for the handset if you're on a six month contract but it could work out a good investment for those who don't want to commit for lengthy periods. Just log on to the online shop, choose the handset and then the site will tell you how much it will cost on different packages.

Their most basic package is €35 a month for 350 calls and texts (unlimited 02 to 02 calls) and 700mb of data (increase to 1GB for €2.50) up to their €70 for unlimited calls and texts, 120 roaming minutes, 120 roaming texts, 120 international texts and 10GB of data.

Make sure to check the cost of signing up online and in store as there can sometimes be savings to be made by ordering from the website. For example, at the time of publication, the Samsung S5 can be purchased online for €289 with a 12 month contract of €39.73 for 500 minutes and texts (unlimited O2 to O2 calls) and 1GB data. To get the same deal in store, the handset will cost €299 (€10 more) and the monthly contract will cost €45 (over €5 extra a month).

Vodafone

Vodafone has a standard 24 month contract for all smartphones so you can either sign up for one of these or choose to pay the full price for your handset and get either a Pay As You Go package or a SIM-only billpay package (30 Day or 12 Month contract).

Their basic smartphone contract plans include €35 for 100 any network minutes (unlimited to Vodafone customers), unlimited texts and 1GB data or €40 for 100 calls to any network and unlimited texts with 1.5GB data (promotion currently offering double date for first six months), unlimited Vodafone calls and the Red Extra Entertainment Pack (six months of Sky Sports or 24 months of Netflix or Sky Sports Mobile TV.

The network's highest package is €80 for unlimited calls and texts with 14GB data with 4G, 500 international minutes, 500 international texts, a new phone each year and a RED Extra Entertainment Pack (as above).

Again, Vodafone run a series of offers online so be sure to check what is available when you're shopping.

Three

Three offer either an 18 or 24 month contract and a shorter term billpay SIM only contract.

Their smartphone plans range from €25 for 100 flexi-units (one minute or two texts), 4G All You Can Eat data and unlimited calls to Three customers to €55 for unlimited calls and texts, 4G All You Can Eat Data and one free add-on.

Tesco Mobile

Tesco offers a choice between a 30Day SIM only plan or a 24 month contract, ranging from €10 for 100 minutes and texts with 100mbs of data to €50 for unlimited calls, texts and data. All plans include free Tesco to Tesco mobile.

E Mobile

Eircom offer a wide range of packages, with different options available for those who have iPhones and those who only require calling and texting. Contract lengths range from 30 Day Sim Only to billpay of between 12 and 24 months.

Their basic smartphone package is from €24.90 and includes 100 any network minutes and texts every month plus 1GB of data and unlimited free call to landlines, while the 24 month plan 4G plan is €55 and includes unlimited calls and texts to any network, unlimited calls to all landlines and 5GB of data.

The message - shop around to find the best deal and your pocket will be happy in the long run!