We are still amazed when we find customers using the biggest box they can find, then filling it with the heaviest items they own, like books or tins of food. We recommend using smaller more manageable boxes for your heavy items, and save the larger boxes for the lighter items like duvets & pillow.
You want to get yourself some good strong, sturdy cardboard boxes that can take a bit of weight in them. A good mix of small, medium an large is usually enough for most homes to be packed up ready for moving day. Other essentials include packing tape, packing paper and bubble wrap for your precious items.
It doesn't hurt to label the boxes either, so you know which room to put them in when you arive at your new home.