The main storage areas in your home are probably the attic and basement if you have one. These areas of your home seem to just accumulate more and more stuff to the point where you can’t move around. Take the time once a year to go through those boxes, and figure out if you really need and use them. If you determine you don’t really need or want it, consider giving it to a family, a friend, or donate to a charity.
Take a methodically approach to cleaning these storage areas. Keep the areas around hot water heaters, fans, and air conditioning units clear from any storage items. Go through the storage areas and discard items no longer needed.
Take general cleaning processes to clean the windows, walls, baseboards and floors. This involves vacuuming, dusting, and mopping if appropriate. Here is a video from Howcast on some ideas.