I ask people to take responsibility for and organize their own packing and shipping. For those not getting free or almost free material, I will try to help with shipping, insurance, packing, etc.
The cost of shipping can be higher than the cost of parts. I am not a shipping specialist, so I pass that issue to those who are interested in getting equipment to arrange their own shipping. Everyone can hunt the web for comparative shipping prices for particular packages. I hope you see why I pass this back to those interested - so they can get just what they want and save money (try starting with: http://www.google.co.uk/search?hl=en&q=shipping).
UK postal service shippers (Parcel Force) have a weight limit of 30kg. They are a good balance of economy and reliability.
Used flight cases can be an excellent way to package computer equipment.
I have had success with: http://www.spider-engineering.co.uk/
I put everything possible in bin liners to help prevent ingress of damp.
FedEx, UPS, DHL, etc. - the usual culprits, are outrageously expensive and
not worth considering.
The sort of companies worth considering are those that deliver where speed is not the critical issue, for instance house moving shippers who mass shipments for one destination and send by sea.
For those in Europe, I recommend firstly to confirm carefully and thoroughly with me what they want/need. Pre-arrange with me and come over with car or pickup as required. We are very convenient from major motorways, and 1/2 hour from the Continent and Channel Tunnel terminals.
Shipments have successfully been sent from here to Europe and the US on many occasions.
Only one item (to my knowledge) has been damaged in transit. That was the pointer for a ZedPen which the US customs destroyed - I suspect because they suspected it of being a threat to national security. I cannot take responsibility for such eventualities and recommend that you insure your shipment fully (including the price of shipping).