First of all, please forgive me for mentioning the word "Christmas" in September – I know, it shouldn't be allowed. However, this heads up will save you lots, if you are planning to send Christmas presents overseas. Don't miss the boat for sending gifts via sea mail, since the airmail alternative will cost you much, much more.
If you were going to procrastinate on this issue for a while longer then you are out of luck. The deadline is fast approaching; with the last sea mail closing date for the UK, for example, being 21 September, 2012. Most of mainland Europe is a week later on 28 September. If you are sending to South America your ship has already sailed (closing date for Christmas 2012 was the 17th of August). I sent my Christmas gifts at the end of September last year, to both the UK and South Africa. You don't really want to know when they arrived. Let me just say, the recipients were rolling their Easter eggs; having long since been convinced they were out of favour. Yes, I am actually serious – I posted my gifts in September and they arrived the following April. So the lesson here, is that if you are sending items, get them ready and send them now. You are still restricted somewhat by size and weight for although the sea mail rates are cheaper, you will still be spending a significant amount in postage.
Check here for the current "easy guide for International postal charges". First of all, check what zone your item is being posted to e.g. the UK is Zone D. Then check the weight of your package. At the moment, the cheapest international parcel you can send, must weigh under 250g and will cost you $7.75 (air: $12.50). Between 250 - 500g is $12.30 (air: $21.25) and 500 – 750g will set you back $16.85 (air: $30). The maximum weight limit is 20kg, which costs $39.60 (air: $73.75). I've listed the airmail charges in brackets so you can see the difference in cost. If you were going to be posting the item anyway, then send it now, by sea, rather than nearer Christmas, by air and put the extra money into the gift itself, instead of the pocket of the postal system.
I'm sure there are people who are very efficient about all this - mine usually becomes the September rush instead of the December rush. They will no doubt stock up on Christmas paper and cards in January, for the next year, since you will soon discover when you are about to wrap, that there is no Christmas paper to be had in the shops. Don't give up – tissue paper in gold or silver, with a coloured ribbon will look just as festive and be nice and light. You can also buy lovely organza bags in gift shops for small gifts.
The up side to all this, is the fact that if you have relatives overseas that you send to, then your main Christmas preparation is all behind you by September. I have to say that really takes the pressure off Christmas and leaves you to enjoy the festivities, without the frantic rush that often clouds December.
Oh, by the way, these last post dates are from Sydney (all sea mail leaves from Sydney), so if you live elsewhere in Australia then you need to allow extra time.