Selling on eBay is kind of an art. I'm by no means a power seller or anything of that sort, but eBay has kept me entertained for quite a few years now. I have sold quite a variety of products, mostly used supplies that I figured would be better off in someone else's hands than collecting dust in my home.
The best thing that you can do for your listing is to take the maximum amount of pictures allowable of your product (before the fees for extra slots begin to kick in). Make them good. Reveal exposing details of what you're trying to sell, and collect all angles, because there is nothing that boosts confidence in the buyer more than showing him exactly what he will be purchasing.
For example, I'm selling a laptop right now that has some great offers on it. I've taken pictures of the top with the power adapter, bottom, what the computer would look like if you were to sit in front of it with it switched on, and the dated screens showing the specs. Within 12 hours of posting the item, I have offers within 10% of my asking price, and the reason I haven't taken any of them yet is because I am waiting just a little bit longer to see if anyone will bite, even though I understand that there's a psychological tendency for buyers to low-ball off the listed price.
And that's another tricky part. Being able to price your items optimally takes a bit of practice if you're not used to utilizing the information available to you. But my rule of thumb is to typically compare to similar items of a similar quality on eBay, Amazon, half.com, etc. Think of any websites that could be selling what you're trying to post up, and make sure that you undercut by a reasonable amount. I think a good rule of thumb is that if you're looking for a quick sale, a 15% cut usually does the trick, especially if you are able to incorporate a cheaper shipping method than your competitors. I think this is much easier said than done, as I've sort of mentioned, pricing is kind of a balancing act. Your intuition of the eBay markets will become refined with more practice in just the art of selling.
A third strategy is to stuff as many crucial keywords into your title as humanly possible. For example, when I'm selling a collectible sports card, I include words such as TROPHY, PROMO, COLLECTOR'S, and RARE. I have had people purchase sports cards off of me without a precise intuition of what the valuables were worth; what made a $30 set different from an $800 set due to history and card condition. But aptly describing my products in the titles and in the body description, using bold letters and spacing in a strategic manner which indicates intelligent writing, have given me great success in the world of eBay.