Hi Blondie,
Many companies ship differently. I have ordered from only 4 different places and some are more worthy of praise than others. They ship it boxed with lots of peanuts and/or other fillers to keep it from moving around, and it is wrapped heavily in newspaper or other type paper for cushioning and taped securely for shipping. Even if your orchid has a spike or blooms, they usually do a nice job securing it around stakes and using cotton so nothing happens to it. There's always the possibility of your blooms blasting due to the stress of travel, but I have only had that happen once. And they usually ship it to be delivered within two days tops....using Fed Ex, USPS, or UPS.
They make sure the plant is well tended before shipping so it won't skip a beat as far as care goes.
Now, I am talking about reputable orchid places, and I do not know about ordering from individuals or on ebay.
More often than not, people who buy/sell orchids take special care to make sure the plant is sent properly. Positive feedback it very important to them.
Also, there is a vendor feedback here on OB that you can check out. Or ask anyone here if they have dealt with the company you are planning to order from. They are all so helpful here. It's hard to go wrong!