When I am hired to do a whole house purge, I always start in the basement or attic. Time and time again, this mystifies my clients. Why do I choose these areas? These tend to be the places of the forgotten stuff. By cleaning out the attic and the basement, you provide space for items that don't need to be in the main living space.
When you clean out your attic and basement, you need to zone the areas. By zoning, I mean organizing by category. Some of the categories that should be included in your "cold" storage space include:
1. Holiday items
2. Seasonal Sports or Activity items
3. Memorabilia items
4. Off Season clothes
Basements are also a good place to set up what I like to call "overflow" areas. These can be for kitchen items or bulk shopping. Its also a good place to store clothing that you are waiting for your kids to grow into. Make sure that you label what is in your bins.
And after you tackle the attic or basement, then I would move up to the main living area. Usually I tackle the kitchen next!!