And finally the million-dollar question “What should I sell?”. The best answer I can give you is that you should sell whatever you can find cheap. There are people who have made successful businesses selling socks, paper clips, screwdriver sets, cake pans, plastic bags, pet supplies, airplane parts...etc. Again, I will reiterate that people are looking for a bargain, so whatever you sell, you will need to find is at a super-super-cheap cost to you..... so that you can sell it for a bargain-basement price and still make a profit.
Of course, you should always search completed listings and see how popular something is and what is considered a good price for it.
You can never predict 100% which things will sell, but you increase your odds of success by going with what is popular. (Like I said in the beginning, new, mass-market and brand name items)
New: Buyers like new stuff better than used stuff (obviously) and especially since everyone is trying to undercut eachother and have cheap prices, you will find new stuff selling for very cheap. If you have a used item to sell, you might be able to sell it, but your price will have to be cheaper than the new items on ebay.
Mass Market: Although someone might buy a one-of-a-kind artistic hand-painted spice rack, this is a one-time purchase and for every one of these buyers, there are 100 buyers who are looking for a plain, boring Rubbermaid or Tupperware storage container. Especially in a tough economy, people are shopping for basics and not luxury items or fancy stuff.
Brand Name: Buyers like brand names because they know they can trust the quality of the item, since they can't pick it up in their own hands. Also, this has a lot to do with search results.
Am I telling you not to sell jewelry, hand-made judaica, crafts...etc? No. I am just saying that you should seriously investigate your Ebay competition and determine if your beautiful and unique items are getting buyers (and if they're fetching a decent price). You will likely find that Ebay is not the best venue for these kinds of items. The kind of buyers Ebay attracts and the kind of buyers a site like Etsy.com attracts are quite different.
Another thing to consider is that most buyers are in the US/Canada and Europe and to think of what they would want and what they would search for. This means looking out for well-known brand name items that people in other countries would know, which is not necessarily the Israeli brands that we have here. The other reason to sell brand name stuff is that there is so much on ebay that someone searching for almost anything can get overwhelmed easily.
The big question to ask is WILL MY LISTING BE SEEN??? If no one sees it, then no one will buy.
Go on ebay and look at all the search results for “womens jeans” (piles of them, right?) and compare that to “womens Levis jeans” or “womens Abercrombie jeans” (still a lot of results, right?) Buyers first have to find you and if there are way too many listings that pop up when they use general search keywords (“womens jeans”), then they'll start using more specific keywords (“womens Abercrombie jeans” or “size 26 womens Abercrombie jeans”) because they won't look through 20 pages of search results. Maybe if you are selling an uncommon size of jeans, then your buyers will only get a small amount of search results and they'll see your listing. The key is getting customers to find you. After that, you can think about the other stuff like taking beautiful pictures of your items or deciding what the best way to describe them is.
It's against ebay rules to use keywords in your titles that don't actually apply to your item. Of course, you should use keywords that would attract the most searchers – it's OK to describe something as a “Handbag Purse Pocketbook” and use synonyms, but if you're selling a purse from Castro, putting “Gucci Fendi Coach” in your title might get you more exposure for a little while, but it will also get your listing removed.
Ebay has a secret search algorythm (sorta like Google) which gives some listings preference. It's called “Best Match” and you can find sites with tips on how to optimize your Ebay search placement. Usually, when an auction or fixed-price listing is ending soon, it'll be at the top of the list. Also, new items get better placement than used items and stuff from established sellers gets better placement. If you are selling something where 10,000 people have the exact same thing for sale, there is little you can do to put yourself at the top of the list.
There is a wonderful free ebook that explains 'Best Match' which is free.
http://www.auctioninsights.info/bestmatchbook