Here is how I do it
Foam lined box with holes punched in it
A couple of wadded up newspapers
Snake in a bag. (I have only shipped balls)
More newspaper (I make sure the snake is snug)
Heat pack taped to the underside of the foam lid
Seal box
Shipping Label printed off my computer
Yes I "turn on" the heat pack 2 hours before I seal it in the box. As for drop off times I pay the extra $5 and they pick up at my house between 3pm-6pm. And I was planning on using deli cups with wadded up papertowels with my hatchling when they go out next month.
You can pm me if you have more questions!!!