(MONEY Magazine) – On July 10, a lucky eBayer unloaded a used Montblanc Meisterstück pen for $160--not bad for an item that otherwise might have vanished into the back corner of a desk drawer. But Ann Wood of Dallas shakes her head. She sold a comparable Meisterstück just 12 days later for $299: "That seller didn't do his research." His big goof? His description of the pen was "cluttered and unprofessional." Wood would know. She's a PowerSeller, one of 91,000 auctionistas who rake in at least $1,000 a month on eBay deals. They're masters of the online auction--and here are a few of their secrets.

1. MAXIMIZE VISIBILITY, MINIMIZE LISTING COST. When you reach the Pictures & Details stage of the sale process, go with the Gallery option, which adds a thumbnail photo to your listing. That draws sufficient attention to you and costs 25¢. Fussy-looking options like highlighting raise your fees and can deter bidders.

2. DON'T WASTE WORD SPACE. You can use up to 55 characters in the title that appears in a search, so cram in all you can--brand names, model numbers, measurements. Is your item new? Say it. Limited edition? Size 8? Go for it. Also: Could it be described multiple ways--as in "photo" and "print"? Use anything a bidder might type to search for your item.

3. OPEN THE BIDDING AT 99¢...if many items similar to yours are attracting healthy bids. Once you undercut the competition, you'll be shocked at how fast the price is bid up. If your item is special, however--a collectible, say, or an antique--a good rule is to pick a figure you'd be happy to get if there were only one bid, and open the bidding there. (Search for similar items auctioned recently to get a sense of reasonable asking prices.)

4. DON'T JUST REPLY DIRECTLY TO E-MAILS FROM BIDDERS. You don't want potentially crucial information to go to just one bidder. So delete the questioner's name and address and post the query with your answer on the listing. The more details buyers have, the higher they'll bid. --JONAH FREEDMAN