I found these hints/instructions on the eBay DSR feedback system interesting. I might consider copying this into my listings.
Emphasis mine.

Buyers

How to leave detailed seller ratings

You can leave detailed seller ratings on the Leave Feedback page after you leave your overall rating (positive, neutral or negative).

If you choose to leave detailed seller ratings, you must leave them at the same time you leave your overall Feedback rating and comment. When you're rating the seller, please keep the following in mind:

Be honest. Objective ratings help sellers improve performance and help future buyers accurately evaluate sellers.

Review the item title and description before rating the seller on the item as described.

Consider only business days when evaluating communication. Sellers don't always check email on weekends and holidays.

When rating sellers on shipping time, rate the seller on the time it took them to mail the item, not the time it took you to receive the item. You shouldn't hold sellers responsible for delays in mail services, international custom delays or for the time it took for your payment to clear.

When rating the seller on shipping and handling charges, remember that sellers may charge actual packaging materials costs and a reasonable handling fee to cover the seller's time and direct costs associated with shipping. For international transactions, you may also be responsible for duties, taxes, and customs clearance fees as requested by country laws.

Wewy, Wewy, intewesting wabbit!