It's time to start watching Target for toy clearance! Typically things will go in this order: 30% off, 50% off, 75% off. Toys do not go to 90% off unless they are considered seasonal (like stocking stuffers.)
As the stores clearance items, you can find toys in: the toy dept (duh!), all end caps, seasonal section at front of the store, back corners of housewares - by rubbermaid stuff, even in the electronics on end caps. Just make sure to look high and low!
Don't forget to look for seasonal books to be clearanced also. This is the time to start buying for next year...
Another tips: many of the seasonal stocking stuffer toys will work for Easter baskets or Valentine's Day gifts. Think outside of the box. If it is removed from the Christmas packaging, no one will be the wiser.
Happy (bargain) hunting!