We are planning an extensive trip to Europe and we are packing light. We would like to ship our purchases back to the U.S. as we travel through Europe and wanted to know what, and how, would be the best way to accomplish this.
How much do you want to spend? How quickly does it need to get home? How willing are you to trust someone else packing it?
For more expensive or fragile things, it is often best to have the merchant ship it for you if they offer that service. You save the VAT, which is about a wash for the shipping costs. And if you buy with a credit card, you have their protection in case it doesn't arrive or is broken and the merchant doesn't resolve it.
The local post office is the cheapest for shipping. But some are better than others and my experience is they just throw it in a box and tape it up. Not much care or stuffing added. And it is very slow delivery. And many postal employees do not speak English well, so language can sometimes be an issue.
Mail Boxes Etc has outlets in many major cities and will carefully pack and ship via either Fed Ex or UPS (I forget which one). You can buy insurance if needed and they seem to speak English well. But it is very expensive.
Whichever method you choose, be sure to ship to an address where someone is there. Sometimes a signature will be required and you don't want your box sitting on a doorstep somewhere.
My experience matches those above. When mailing heavy items by the cheapest available postal rate, I've often paid about €40 for a small, heavy box. More post offices now have flat-rate pre-paid boxes for international shipments. For instance, France used to sell boxes separate from postage, but more recently I only found the postage-paid kind of box from them (see also http://www.laposte.fr/particulier/outils/calculateur-de-tarif). When I couldn't find a good box to buy, I have also scrounged them from recycle bins. Be selective with your shopping. Things I've had shipped by the vendor have been larger, like carpets.
I use Mailboxes Etc at least once every trip (usually about halfway through an 88-day trip). Not cheap, but schlepping stuff I don't need would take years off my life, I am sure. I usually ship books and clothes I needed for some occasion, plus some things purchased as gifts (for me or others).
I have occasionally had the merchant ship more expensive or fragile items. For other things, I just use the post office where I buy a box and mail using the cheapest rate available. Often I end up beating the box home. Sometimes I mail a box when I only have a day or two left, and then sometimes I use extra clothes as filler to protect the items I am mailing and to make my bag even lighter for the trip home.