I used sendmybag to get my things here from the US. It was really nice: arranged a pickup time at my parents' house, and then it arrived at my door here in the UK 2 days later. It was an enormous bag full of clothes and books and I think it cost something like £50 or £60. They have pretty clear instructions on what you can and cannot pack, and how to pack it. They use DHL, and estimated that it would take 4 days when it only took 2.