Here is an example of a stamp I only have on cover:

It is Canal Zone Scott C5.
I have been racking my brain trying to think of how to reconcile my cover collection and my stamp album.
Here is what I have come up with. I would tell you not to laugh, but really I don't mind.

The idea would be an attractive design that I would impress on heavy paper with a rubber stamp, say, with a tab of paper at the bottom to give information about the stamp.
In this case: CZ-C5 means it is Scott C5 of the Canal Zone.
Second line is CA-1 which means it is in cover album #1. Ex means it is slated to be included in an exhibition I am working on.
Now if anybody had better design skills than me, and better artistic representation skills than me, I invite/challenge/cajole you to come up with something more attractive. ;o)