The safe packing is one of the most important things in selling sculpts,
the strong armature and good quality flexible clay.
This is how I have been packing since the first fairy I sold on eBay,
and it has worked perfectly for me so far, and i have got only great feedback for it.

I choose sturdy gift box which can take good amount of pressure. I cut and glue strong wooden sticks on the inner sides,
about 2,5 cm (inch) from the top, to make the box even much stronger, and then the box can take very much pressure without crushing.
I cut a piece of upholstery foam to fit the box, and then cut it half from about the middle (depending on the pose of the sculpture).
Then I cut an indent to the foam, which is the size and form of the sculpt, but I cut large holes for the hands, feet and the head (ears!).

This is the box with the foam with the indent. I have already put in the strings for tyeing down the sculpture.
The strings go all the way trough the foam, and through the box, and they are placed on the most strongest places of the sculpture,
that is her torso, and the thigh of the standing foot. You can see the wooden sticks there too.

Then I cover the torso and other parts I'm going to tie the sculpture from with thin foam sheet, and place the sculpture in the box on it's place,
and tie it down firmly. Not too tight to harm it, but firmly enough it can't move. If there is still room between the sculpt and the foam,
I put more foam (here you can see a piece of extra foam next to her left thigh), but leave the hands and legs untouched.
There are enough room under the hands there although it seems like there isn't in the pic...

Then I take the other half of the foam and cut an indent for the sculpt, if there is any needed. Usually at least  the face needs and indent.
This is the top piece of the foam. Now it's time to say bye-bye to the sculpture...

...and I finally put the top foam on, and I place a wide piece of wood on top of the box, it goes nicely on top of the glued sticks
on the edges of the box. I have cut a slash in the foam for the wood. This piece of wood prevents the box from crushing from the sides.
The white paper has the wings inside there, they go nicely on top of the foam (if there isn't enough room,
I cut a thin slice away of the foam or pack them separately) Then the lid on, and I tie the box firmly.
The base is packed separately and they both go in a bigger box with peanuts or crushed newspaper which is more economic way.
And talking about econimical packing, the foam is leftover pieces I get from the local sofa factory, no need to buy new stuff for that!