I fold delicate stuff loosely in a bubble wrap envelope, this goes in a small box with plenty of very small bits of polystyrene all around it. The small box (or boxes) then goes in a big outer box, also surrounded with (larger) polystyrene chips or large parcel bubble wrap.
Basically there's bubble wrap, polystyrene, cardboard, polystyrene/bubble wrap again and cardboard again between the model and the postie's level of competence. I prefer to use polystyrene chips instead of paper, because it's lighter for postage.
For some reason, a shredded newspaper never feels like it weighs as much as the original newspaper and it shocks me when I find out that it does!