Once in a while I become paranoid that I have perhaps forgotten to leave feedback on one of my trades, and so I go through and check all of my completed trades to make sure that I actually have. It's easy enough to see a completed trade where you have not yet received a feedback, but the only way to see if you have left one is to go through each trade one-by-one and check them individually. What about a little icon next to completed trades that indicates whether feedback has been left or not, similar to how the pending trades show whether or not they've been confirmed/shipped/received? It could also show up next to the "trades" link (in the same place where the "unread comments" icon goes), when you have completed trades still awaiting feedback. That, and/or an option in the "User Score Details" page to display "feedback left for others" in addition to those received?