While the Delta $50 GC trick was working, I would screen cap the GC number and PIN, then save that in a sub-folder within the CC folder. I have a folder for each card, such as Platinum, Aspire, and Gold, with folders for each year, to save the monthly statement PDFs. So an additional folder for "Gift Cards UnUsed".
Then, as a GC got cashed out, I'd move that image file to another folder, "Gift Cards Redeemed". I have one remaining $50 Delta GC in one of these unredeemed folders.
The other travel credits and free nights are kind of mentioned in my spreadsheet to keep track of various points, but that mostly is used to refer to the card / program website where the next steps need to occur.
