I think i may have asked/talked about this before, but this time it's a poll! :)
Clearly wrapped presents have an "up" side, the side that faces up when you put them wherever you put them for display purposes. (Under the christmas tree, around the hearth, whatever.)
In my experience at least the up side is usually defined by one feature, it's the opposite side from the one where you taped the edges of the wrapping paper together.
So when people open presents my very limited observation is that most people (at least most people who don't just rip off the paper any way they can with wild abandon) flip the present over so they can get at its soft underbelly and rip along the seams.
So how do orient the present when you're wrapping it? So the front of the present will be face up when it's unwrapped? Or so the present will be face up while it's lying around waiting for christmas/birthday/whatever holdiay? We're presuming regularly shaped mostly rectangular presents here, obviously if they're oddly shaped or something the decision may be made for you.