Are the requests starting at your house yet? "Can I have (fill in the blank) for Christmas?" Have you been receiving multiple toy catalogs in the paper and mail lately? Do you feel like every commercial is a ploy to get your kids to ask you to spend more money?
This is the time when the commercialism of the holiday really starts to pick up, and it annoys all of us. Then the questions start to creep into every parents mind, "Where are we going to put said requested toy?". As always, I say to you, none of us NEED what we think we do.
Just like at Back to School time when doing an inventory helps us to not purchase unnecessary items, the same rule applies to Christmas time. Go through your childrens' toys/clothes/electronics with them (depending on age). You will find many things that are no longer played with, broken, or do not fit them. This is a great time to get rid of items that you do not need cluttering up your house, but may also be good items for donations which are so helpful, especially at this time of year.
Help your children (and yourself) to understand that if there is no more room for the new requests then room needs to be created and/or requests need to be reduced.
I always feel that a holiday has been a successful one when we can easily find places to put all of our new treasures away. It is not a good feeling to be drowning in "stuff" that was giving to increase the holiday experience.
I also find that my girls are VERY willing to do a clean up/inventory when they know it is making room for new Christmas gifts. Hopefully it will be a slightly easier request at your home for the same reason. Good luck!