Have your cameras ready 
Be sure to have all the film, video tape, and batteries necessary to take the photos you want or need to get.  Be sure to recharge your video and digital camera batteries.  Santa has a lot of people to visit.

Reserve a special parking space for Santa 
It should be as close as possible to where he is appearing.  Remember, Santa is a senior citizen.  If he parks down the street or around the corner, and has to walk all the way to your home, he might be winded or exhausted when he gets there.  And remember, he's wearing a heavy velvet suit that gets very hot, even in December.  If your house has a driveway, leave an opening at the end of it.   Just put a temporary barrier on the space.  Use a box or a sawhorse.  Have some fun and put a sign out "Reserved for Santa". This makes it easy for him to be fresh and ready to bring joy to your guests.

Get everyone together before Santa enters  
Timing is everything.  Santa will only be there for a set amount of time, and if everyone is scattered around the house, you may lose valuable time.  Santa and you can coordinate.  Santa will do his best to give you an arrival time.  Thats your cue to get everyone together, maybe to sing some Christmas Carols, and to have someone outside to greet Santa. Then at the right moment, Santa can "pop in" and join everyone in their singing.  

Have a sturdy chair for Santa to sit in. 
 Folding chairs and low chairs (the ones you sink in) are not good.  Santa usually likes a chair that is sturdy and stable.  A good straight back dining chair works well.  In order to have children sit on his knee, Santa must sit up wide on the edge of the chair.  He should be able to sit comfortably and have a child on each knee.

Place the chair near your Christmas tree or in a holiday setting
Maybe in front of a fireplace with stockings hanging or any festive type of backdrop.  Your photos will have more impact when the background has a festive look.  Place a wreath, a few Christmas cards or your childrens' drawings on the wall to make a wonderful difference.  Leave a foot or two between the chair and the tree or wall.  This will allow for others to gather around and behind Santa's chair for group photos.

Think about photos with everyone.  
Yes, some teenagers will shy away or think it too childish, to have a photo with Santa.  Dont worry; Santa can stand up for a "buddy photo".  What about grandma and grandpa?  Take a photo with Santa and grandma hugging.  And there is nothing more fun than to have Santa ask grandpa if he's been a good boy!