One thing buyers really appreciate is low shipping costs, but sellers know that not charging enough for shipping can negatively affect the bottom line. Charging only what the U.S. Postal Service, UPS or other shippers charge -- without figuring in the incidental but very real costs such as $3.00 per gallon gasoline, bubble wrap, packing tape, etc. -- will hurt a seller's profit margin over time.

However, with the new, more detailed ebay feedback ratings, keeping shipping costs low is now more important than ever. No seller wants a bad feedback rating for high shipping costs.

There are ways to keep the costs of shipping lower, so that a seller can offer a very fair shipping cost to potential buyers, without losing money.

Here are some ideas in this regard. Taken individually, each suggestion helps a little. Taken altogether, they help a lot more:

1) Put in your listings that you ship twice a week, and name the days -- buyers understand when you are clear about your policy. If you have been driving to the Post Office five days a week, and you cut that to two days a week, you are reducing your driving -- and your gasoline costs -- by 60 percent.

2) Use the smallest possible packages for the item you are shipping. Consider buying manila envelopes in bulk, cutting them down, putting in cardboard pieces to protect items, for a "custom" fit. The smaller the package, the less it costs to ship it. Cut down boxes to size, ship in envelopes (padded or otherwise) whenever possible. Padded envelopes can be cut down to size also -- instead of putting an item that is too big for a standard size envelope into a MUCH bigger envelope, cut down that much bigger envelope to the size you need. And save what's left over of that envelope to ship a smaller item -- or take two envelope leftovers and create another envelope. Little things add up big.

3) Seek packing materials in unusual places. If people have recently moved into your neighborhood, often they will throw out their moving boxes, styrofoam peanuts, bubble wrap and all. Check the evening before trash day, or early in the day on trash day. This saves you money, and it keeps the styrofoam and plastic out of the landfill and the groundwater. You are also conserving energy by reusing packing materials. Packing materials can often also be found curbside after major gift giving holidays as well -- Christmas, Valentine's Day, Mother's Day, Father's Day (and every day is somebody's birthday).

4) Offer at least two multiple shipping options on ebay to buyers, one of which is slower and cheaper. A buyer who is a thrifty sort often is willing to wait for an item to save on shipping costs, and sometimes the wait is not even all that long. Media Mail costs so much less than any other option for shipping heavy books, for example. Parcel Post often does not take much less time than Priority Mail if the buyer is not too far geographically. By offering at least two options, you're showing potential buyers you are looking out for their wallets. They appreciate that.

5) Check the warehouse stores for good prices on packing materials. The prices for padded envelopes at warehouse clubs such as Sam's Club and Costco are considerably lower than at office supply stores. Ebay also has some sellers of packing materials that offer very good prices. Key in all of this is to know what this stuff sells for full price retail. A trip or two to Office Depot and Staples will give you a good baseline on your costs -- work down from there until you find the cheapest price.

6)  Make use of the U.S. Postal Service's flat rate boxes. They are a godsend for heavy items that are not too big, such as cast iron kitchen molds, a collection of marble eggs, etc. Furthermore, with the single rate box, you don't always have to use expensive styrofoam peanuts as protective packing for your items. If the items are not too fragile, and you just need packing material to keep the items from shifting around during shipping, use crumpled up or shredded newspapers or shredded papers. The price for shipping is the same, and it doesn't matter that you are using heavy(ish) newspaper rather than lightweight styrofoam peanuts.

7) Always offer buyers a lowered combined shipping cost for sales of multiple items. It's a volume discount -- on shipping -- and everybody likes a discount.

8) Don't estimate weights in your listings, because it could lead to inadvertent overcharging or undercharging. Buy an accurate scale (one that goes only up to five pounds is not that expensive, and is adequate for most items), weigh the item, add on the weight of packing materials (varies for the item), and run the U.S. Postal Service's online calculator, using the combined item + packing materials weight, for domestic shipping from your zip code to a far point in the United States. Alternatively, you can ask your buyers to use a shipping calculator.

9) Use sturdy boxes, but not thick and heavy boxes that add to the weight, unless it's absolutely necessary to have that type of box.

10) Buyers are not fooled by sellers who offer unbelievably low "buy it now" prices for an item, and then pad the shipping costs ridiculously high. Start the bidding at the lowest price you're willing to accept and be fair about the shipping.