I have one of those plastic carts with a tall bottom drawer, a little over 12" high. I stand my 12X12 paper up in the drawer and organized it by category I would probably use it for. I took a piece of cardboard and put a file folder label on top for each category. It is easy to flip through and find what I want. I've listed my categories below, but am sure you would have your own that would work better.

Here are the categories I started out with...

GENERAL - Largest group,everything that didn't fall into other areas. Just papers I love and I organize them by color within the general area.

TRAVEL - Cruises, Hawaii, Mexico, Car Trips, etc.

FAMILY & FRIENDS - Papers with wording or sentiments that I feel would be used for Family and Friend pages. My heritage paper is in here also.

KREIG - This is my husband. Anything specific to us really. I could have labeled it Kreig and I or US. We have a Harley, a boat, a tent trailer, so anything that fails into things we do together.

HOUSE - We bought a house 3 years ago and it is still a work in progress. I love documenting the upgrades we do ourselves.

HOLIDAYS - Any holiday goes into this area, grouped by time of the year. I group my starting with the first major holiday Valentines Day, so Christmas and New Years are at the very back.

BABY - We don't have children, but have friends and family who do, and I also use my paper for card making and love to use these papers for baby cards.