There is something magical about TV advertising at Christmas. I'm not referring to the annual competition between John Lewis and Marks and Spencers (though a hedgehog on a trampoline gets my vote every time), but to the instant transformation that occurs on Christmas Day itself.

After weeks of encouraging us to stock up with booze and mince pies, literally overnight the TV switches to selling us holidays. It seems that we all need a break in the sun to help us recover from the "most wonderful time of the year".

Mission agencies can't generally afford TV adverts, but around now, lots of young – and not so young – Christians are starting to think about going on a mission trip for a few weeks next summer, or maybe for their gap year.

If you are thinking about a short-term mission trip next summer, here are a few things that might be helpful.

1. Talk to your church leadership as soon as possible and get their advice and input. Nothing excites church leaders more than seeing people want to go all out for serving the Lord; it's why the do the job in the first place. However, very little frustrates them more than someone coming up to them in June and saying that they are heading out to Botswana in two weeks and would the church like to pay for it.

2. Go with an organisation that you've heard of. Choosing an organisation for your short-term trip can be very confusing. The best bet is to pick an organisation that are well known and that you or your church already know a bit about. There are a couple of reasons for this. First, well-known organisations are likely to be more professional than small agencies that you've not heard of. Second, if you can build on existing relationships, your mission trip is likely to be more fruitful for you and for the people you are going to serve.

3. A word of warning. As the former director of a mission agency, I'm not supposed to say this; but here goes anyway. Mission agencies know that young people who do a short-term mission trip with them are likely to turn into long-term supporters or even career missionaries. However, the best agencies will encourage you to look around to find the best fit for your interests and gifts. Avoid the agencies that give a hard sell and go with those that give good, objective advice.

4. Make sure they will look after you. Going to Burkina Faso for a month is different from spending a week in Ibiza and it's much more of a challenge. Make sure that the organisation you are going with has structures in place to help with medical issues, cultural challenges and the like. Ask them about medical insurance and post-trip debriefs. If they don't give satisfactory answers, go with a different group.

5. Do no harm. It can be really exciting to go out to the developing world and help to build a new village school. That is unless you are the village builder, who has lost his income because he's been replaced by a bunch of young Brits who are working for free. Orphanages are a particular problem. People love getting to know the kids and bonding with them for a few weeks, and taking lots of cute pictures. Meanwhile, the kids in the orphanages quickly learn the lesson that it's not worth getting attached to adults, because they never stay for very long. I know it sounds cynical, but there is good money in orphan tourism. Children are taken away from their extended families and put in orphanages so that rich westerners (that's us) will pay good money to come and look after them.

6. Have a break. If you've travelled all the way out to Thailand, you'd be bonkers not to spend a few days having a holiday at the start or end of your mission trip. Long-term missionaries know all about the best (and cheapest) places to have a good break – get some advice from the professionals!

7. Look for the seal of approval. If you were booking a package holiday, you would want to know that the company selling you the break was legit. The equivalent for mission trips is the Global Connections' Code of Best Practice for Short Term Mission. The agencies and churches that sign up to this scheme all aim to meet the high standards in terms of care for the team participants, discipleship and the ethical impact of what they do. If the group you are interested in is not registered with this code of practice, you should ask them why not.

Above everything else, prepare yourself. Pray for your teammates, the people you will be serving and even for yourself. Read up about the country you are going to, see what you can find on YouTube or Facebook that might give you an idea of what to expect. Go expecting to serve and hoping to learn and have a blast!

Eddie Arthur is director of strategic initiatives for Global Connections, a network of UK agencies, churches, colleges and support services that seeks to serve, equip and develop churches in their mission.