Whether you're a buyer or seller, it's good to leave feedback so members know if the person on the other end is easy to deal with. To get started, click on the number beside "Feedback Score". You can also access the a person's feedback score by clicking the tab under their profile.
From here, you can see more details from previous transactions. Click "Submit Feedback"
It will then bring up an editor box where you can enter details about your transaction
Use the drop-down menus to tell if you were the buyer, or seller. Under "Overall Experience", you have the option to tell whether the transaction was positive, neutral, or negative (You must choose one). You have the option to add the link to the sale thread. Next, enter a quick summary of the transaction which will be visible to everybody...and finally, additional comments, which are hidden from public view.