In my line of work, one of the most common reasons I see houses get so disorganized is because the owners have a great system for getting stuff into the house (shopping, gifts, freebies) and no system for getting stuff out of the house.
If you keep adding to the contents of your home without ever removing much, you will eventually run out of space. At this point, it would be unwise to chalk up this problem to lack of storage space, easily fixed by $200-worth of product from Storables. Instead, you must take the time to sort through your stuff, and discard what you do not love or do not use. If that sounds time-consuming to you, you’re right.
Prevent that headache by putting into place a discard system. You could make a rule that for every new piece of clothing or accessory you bring home, an old one must be discarded. You could start holding an annual garage sale. You could create a donation center in your house, making it convenient to stash your unwanted items as you come across them. You could walk through your house once a month with a big garbage bag, collecting all the cast-offs as you walk by.
So the next time you are looking around your house and wondering how it became so cluttered, ask yourself, do I have a system in place for making sure stuff leaves the house? The answer to that will put you well on your way to living in an organized space.