One of the best ways to organize your home and keep it clutter-free is to have a firm grip on everything that enters it. The more possessions, the more quickly they seem to get disorganized.
There are lots of strategies that can help control the inflow. You might make a rule that if you plan on buying something new, a similar possession you already own is going to have to bite the bullet. Doing this can call to mind a crowded closet or overflowing shoe rack and put the purchase in perspective. Plus, it can also help maintain a budget. This type of tactic may be useful after a child's birthday as well -- each new toy received replaces an older, outgrown one.
Another good way to get organized is to evaluate items for other potential uses. You might have bought a cabinet to store old magazines, but if you ditch the past issues you've got a great place to centrally store a photo collection.