shipping a neonate?

i have never shipped a snake as small as a neonate. now that i have a buyer (or hopefully soon) i need to know how to ship safely. i shipped some boas via ups before, i put them in pillow cases and placed them in a styro lined box, with newspaper lining to reduce movement. i was planing on doing the same thing, but the snake will be in a deli cup. my question is, what do i place in the deli cup to reduce sudden movement of the snake? shoul di just fill it with aspen, or napkins, or what should i use?
thanks

I put a paper towel crumpled up in the cup with the baby.

I've just filled the cup about 2/3 full of aspen. This gives him enough room to move around but at the same time they can bury in the aspen for security and for "bump protection."

I've used both paper (paper towel or kleenex) and soft, shredded aspen in the deli cups with my babies. I also put the deli(s) into a snake bag so that the snake is contained should, heaven forbid, the box gets crushed enough to pop open the deli or the snake is able to push open the lid. I also will sometimes tape the lids of the delis for extra security.

I then pad the bottom of the box, place the bag with delis in it on top, then pad sides and then the top. I use thick styrofoam-lined or solid styrofoam boxes within a cardboard box. I seal the boxes tight without air holes (yes, those babies have plenty of air a 12x12x12 or 8x9x12 box for days, easily) to reduce temperature fluctuations and use a warm or cold pack if necessary. This time of year is perfect for shipping, so usually none are needed right now. Be sure to check temps at your home, the shipping destination, and the shipping hub in between.

Basically pack the box so that if a 260 pound gorilla starts slamming it around, that the snake is secure.

thanks for the quick replys, that was pretty much my plan, i just wanted to make sure.

one more question,
UPS or FEDEX? and why?