At the moment, I record trades by uploading screenies etc., deleting them, and then writing the links to the pics related to the trade in a .txt file.
I sort my files out like this:
ex.
230611 Skilling 25 the dealer
So:
[date] [type] [price] [user]
Also, I compress it to a .rar folder, and save as .jpeg ... it's so much easier to upload
So due to .txt s being so small, I only have about 2mb of Sythe-st00f.