It becomes a little headache if I don't organize it and it'd better be sooner than later. Here is just my way of organizing them, making it easier for me to grab them once they're sold out:
- Enclose the card and envelope in a plastic sleeve
- Number each card and make sure it is corresponded to the listing. I bought labels and they will for a long time since they are 500 at least in a pack.
- Store them in a box :-)
As I'm organizing these new cards, I found a box of Christmas cards that I made a couple of years ago. As I haven't made any new Christmas cards, which I should anytime soon, this will be a great start to list them on my shop.