It's funny seeing everyone's OCD behavior with these.
If it's a 25th carded figure, I always buy 2. This has obviously gotten expensive as fuck since the 25th came to a close, since anything is at least $30+/per figure and a goddamn exclusive. The best card stays carded, the other gets opened. If I'm lucky enough to get something like, say, 10+ Jinx, I pick the best 2 for the carded/opener of the lot then sell or trade off the others over time.
Anything since ROC, including POC/30th, I only buy one since I dislike the non-vintage card art. This at least saves a little money, I guess... I just look for the best eyes and paint apps, and make sure there is no molded damage to the actual sculpt in-store (on the few occasions that I actually
find something in a store), and then I buy that one.
If it's a troop-builder, I generally open one first, wait a few days, and then open the rest up in case for some reason I end up hating the figure and don't want to keep the others. The last time I really got a bunch at one time, was in my BBTS POL when the 30th figures all released at the same time. I generally stand them up on my coffee table, and mess with them for a few days until my girlfriend gets sick of seeing them and I have to move them to my desk in the guest bedroom. From there, they may get modified or whatever.
The only "almost always" thing I do with any figure I open, is toss the plastic shell, toss the stupid stand in a giant bag full of all my other 25th/ROC stands (they're at least separated by ROC/25th) and then put the flat, full card in a drawer. I'm not really careful when tearing off the bubble, but I do keep the full card generally, and try not to bend the card itself. The back is usually partly torn off, though. Some guys use an X-Acto to cut them off, but I couldn't care less. I think the torn backing makes it feel more nostalgic, I guess?