I have catalogued all my stamps almost from day 1, and it is really good as you do forget what you have! My stamps are in Joanna's folders, loose-leaf files, and a set of A4 clear plastic storage files, which hold most of them. Each file is identified in the catalogue so I can go straight to the right place.
It also stops me being tempted to buy new ones, as I look through the files first before I part with any more money.
I keep all the sentiments, Alphas etc in one place rather than littered through the system.
HTH
Judy C