Sometimes there is no solution. A space is just plain maxed out. I walked through such a home the other day. I could only come up with three solutions since the client didn't want to purge(and I am an organizer). Here are a few ideas to help you de-max your space.
1. PURGE..Yes I said the "P" word.
2. Look at the configuration of your shelves. The other week I reconfigured a clients closet shelves and then we we able to add 7 more of them.
3. RELOCATE..Relocate your items. What can be stored in other areas of your home
4. LIMIT THE INCOMING..I was in a home that had a ton of food. It turns out that there were only two of them. Limiting the incoming not only saves space but waste as well.
5. Use all your Vertical Space! Tall bookshelves vs short!
6. Use empty wall space.. Think cabinets
7. Store items on top of your kitchen cabinets (totes or wicker baskets look nice up there)
Sometimes it just takes a little creativity to make things work!!