I've been living in the same apartment for 12 years. In that time I've become pretty good at living with one closet, one sink, one guitar-obsessed husband, 2 cats and lots of stuff. I wouldn't say I'm a pack-rat, but I'm certainly no minimalist.
I had always assumed that our place was about 750 square feet -- I think that's what the landlord told me and I just never bothered to check. So when my husband and I started looking for a place to buy, we finally measured our apartment and found that we had actually been living in 498 square feet. Overnight things seemed almost unbearably claustrophobic!
What a great time to start my jewelry business, salt & paper, quite literally on my kitchen table! Storage became a huge issue almost immediately and so I found what seemed to be the only space left in the entire apartment and put it to work. The 9 inch gap between my pots and pans and my kitchen cupboard became my bead library. I installed a 1" x 3" plank as a long shelf. The original plan was to recycle baby food jars, but that would have required our consuming a lot of baby food (sans baby) so I finally bit the bullet and ordered cases of empty plastic jars. I organized everything by color, and filled up the shelf. I also added a magnetic strip (used to hold chef knives) to keep all my tools at hand, and making it easier to spot when my husband "borrows" some pliers to restring a guitar.
And just when I got everything organized... we found a house. Today we closed on our new house, which is just over twice the size of our current place!