I know everyone still has Christmas on the mind being that's still 2 weeks away. However, now is the PERFECT time to start planning for next month. (What can I say? I'm a planner.)
As soon as you've finished your Christmas prep (or if you have a minute to spare) (I know...I'm hilarious! Free time! That's funny! But I digress...) When you can (how's that?), make a list of all of the birthdays you have coming up this year. Include not only your kids, but any family members or friends who you know you'll be buying presents for in the coming year. Write down ideas of what you want to get them as well as a price limit for the gift.
Then hit the stores in January! All stores start a massive toy clearance in January. Some stores go more quickly than others. Wal-mart tends to clearance their toys out the slowest. Target is usually the fastest with some stores hitting 75% off by mid-January and others hitting it by the 3rd week in January.
A word of advice: If you KNOW that you want something at Target, then buy it when it's 50% off; especially if it's a hot item.
I also start planning and buying for my Christmas NEXT year (in 2011) in January. Like I said...I'm a planner!