When I say big hole, I mean BIG hole.
If you use a pot like that one on ebay, I really would suggest the hole-in-the-middle method, the moss ball should look something like this on the inside:
Here's an easy way to get the same result basically:
While the hole in the middle isn't absolutely necessary as long as you control the watering and density of the moss well, it goes a long way to help preventing overwatering and root rot, especially when using non-porous pots.