I too store mine in the original packing stood up in boxes, as flicking through them is the easiest and quickest way to find what you want. Each box is roughly categorised into cute, animals, sentiments, Xmas, vintage etc so I don't have to flick through them all.  Sometimes I add a sturdy piece of acetate to stick the stamps to for stability if I've put unmounted ones onto Ezmount .
Jo, I've always intended to stamp them all to create a catalogue but never got round to it and now I've got hundreds that will take weeks to do!!
Cassie x