I have a template I use when selling anything. You can see it in a few of my past auctions here: one and two.
Most of the pics are gone from the first one, but still there on the second. I believe that picking the subject/title is absolutely imperative. Use every possible good key word you can think of that applies. In that first auction, I even listed an abbreviation for “Wizards of the Coast” because I’m positive many people search ebay with it (and they did publish those games I was selling) plus two variations on the spelling of the name of the boardgame.
Also, as Bull briefly alluded to, pricing is important. If the similar item is selling everywhere on eBay for $20, having $25 as your opening bid won’t cut it. :) If you must get a certain price, use the reserve feature. Also, there’s almost no reason whatsoever in any instance to start an auction above $1 (unless your “opening bid” is the minimum you’ll accept… then it’s kind of like starting at the reserve price).
Beyond this, I use the layout you see in both of the auctions above (side by side, they look rather similar). First a brief intro paragraph (here’s where you pack it with more key search terms, such as using hyphens or breaking compound words apart). In here you can also include other, related terms people may search for (such as when I listed “Magic: the Gathering” in my boardgames auction). Then I put up pics, which are all linked to extra-large versions (like 1280x1024 or more) so people can see the detail on precisely what they are getting. Then a description of the pics. Also links to related things are cool because people can see just how exciting your item is, such as my link to a Google search of board game cons, or in previous arcade machine auctions I’d link to the KLOV entry. Finally my standard language closing paragraph concerning payment, shipping, etc.
I always use the 7 day auction because it gives plenty of face time but doesn’t cost extra. I always start my auctions on Mondays, because this fits in a weekend right before the end, but not too closely. When someone asks me a question using the eBay tool, unless it is a repeat or retarded, I always post the answer on the auction page (both of the above auctions had questions, eBay automagically added them to the end of the auction itself so you can see how they look).
I’m not any kind of a power seller or anything, but this formula has worked for me many years. Parts of it, such as the Monday fixation, may be totally invalid but they at least have not totally unreasonable hypotheses as my intellectual backup. I’m 100% confident that title is key, and pricing and good, high quality pics are important. I’m not big on the flash and jazzy layouts that most power-sellers use, but I think that shows the buyer that I’m more of a person than some company on eBay.
I’m posting my last arcade machine for auction tomorrow (finally). When it’s up, I’ll link to it so you can see how it sticks to the same template.