Pack like locusts is a perfect description!
We put everything we did not want them to pack (what we would need for 24h, plus hoover, kettle, personal documents, jewellery) on our bed, and then let the packers rip.
They labelled every box with the room it came out of, but, because I was not able to be around for all the packing, I didn't manage to label all the boxes with their destination room. So when they unloaded at the new house I stood at the door and told them which room to put each box in as they zipped past me. It worked perfectly.
They had special boxes for clothes: shallower ones for the contents of drawers, and tall ones with a bar for clothes on hangers. So when we unpacked everything came straight out of the box into the appropriate drawer or wardrobe. I didn't even have to refold anything.
They dismantled all the beds and rebuilt them in the new house, first checking with me where exactly to position them in each room. The bedside cot puzzled them, and they needed help from me on that one.
Anything fragile was bubble-wrapped or paper-wrapped before boxing. Anything that could not be boxed was bubble-wrapped and/or wrapped in blankets. They took the blankets and hanger boxes back afterwards, but all the other materials they were happy to leave or remove as we chose. The only breakage was a new thermometer that was still in its blister-pack.
It took them 2 days to pack up a 3-bed home, leaving just our 24h+ stuff and mattresses for us to sleep on. The lorries with our belongings were in safe storage both nights. On the 3rd day they packed up the mattresses, we took the 24h+ stuff in our car, and we left.
Money well spent.