In our house, stockings are hung above the mantel piece (empty) before the children go to bed and are filled/put on beds when the adults go to bed (usually after midnight mass).
Any presents given from friends etc are put under the tree as they arrive in the house.
Each child has a big, personalised, Santa sack which is brought down (usually before mum and I go to midnight mass) and if presents don't all fit then they are arranged around the sacks in "areas" of the lounge so that each person has there spot to try and contain the mess!
This year, dd1 has an ipad and other three children have kindle fire tablets that I am going to keep back until later in the day (so that they show some interest in other presents!!!).
Dh's parents usually save their gifts til Boxing Day when the children go in to see them.
We try to eek it out a bit, so that they appreciate everything, but obviously the sooner they are opened the sooner we can clear space to sit down! (Little room!)
They also have "dinner presents" (this year will be kindle vouchers/iTunes vouchers and a posh chocolate, something small) in little tiny stockings on the dining table. This year, for the first time dinner is going to be about 6pm as opposed to at lunchtime because nana (who lives with us) is working 2-5pm on the big day.