Storing stamps
Shoe boxes, pencil boxes, video cassette boxes, Iris carts, book cases, baskets, shelving, banker’s boxes, storage boxes.
UMs: CD jewel cases, envelopes,  cling system/page protectors (stamp image on cs, insert, put UM on image)
Small stamps can be kept inside a floss box.
Small UMs can be housed in trading card sheets with an image.
Alphabet stamps can be kept in Ammo storage boxes.

Classifying stamps in storage
Some people classify by theme or company.
If you classify by company, you can also classify by theme in a notebook, just stamp the image.

Paper Storage
Some people classify their paper by company, some by color.
Some do not break up a bound stack or set from a company.
Literature/brochure files are convenient.
Magazine holders that are sturdy.
Wire racks.
WalMart carries 12×12 draws also.
Craft shops carry 12 x 12 accordion folders.
And then there are the 12 x 12 art bins that are clear and stack-able.
Iris now makes a scrapbook cart to hold paper and tools.

Recyclables for small stuff
Tic Tac containers
Pringle cans (rollers)
Altoid tins
Bead containers
Picnic utensil holder (markers, pencils)
Old dishwasher utensil holder (markers, pencils)
Thread box (wire spools)

Curtain rods (cafe or spring)
Box with holes poked on the sides, pull out ribbon
Paper towel holder
Mug rack
Glass jars — fancy spaghetti sauce jars are nice!
Peg clothespins — wrap ribbon around them

Clear boxes
Over the door clear shoe bags — some people hang them from the wall or ceiling.

Portable Storage
Tool boxes — even a large tool box on wheels can fit in a closet if you lack space.
ZAG Workforce 25 compartment organizer — holds ink pads and rollers

StampinUp sets
Stamp set images on cardstock, label set and number, place in page protector in a binder.
Put the same number as the stamped page on to the side of the storage box.
Put in numerical order so the number is facing out.
You can use old VHS racks to store sets, baskets or a shelf area in a closet/cabinet, or a set of draws.

Related article —  My own storage list — what I use in my space.