ok - maybe this isn't a huge tradition - this is probably what normal people do.
In my home, only one person at a time opens a gift, that way they are the center of attn & everyone sees their reaction.
This is different than when I was growing up in my parents home - my brother & I just tore into the gifts, one after another
The one at a time does take awhile, we video tape it all & it makes sure that we get all the family members on tape.