By browsing the advertisements I see that mistake many times which is the short, unimformative description. So, my first selling tip would be for successful selling is also the most important: make great title and description about what you're selling!
The most important purpose of the listing's title and description is to describe the item. A good title describes accurately the item which is listed, and which is the most important: makes our advertisement searchable.
The searchability is the most important for advertising, even more important than the good product photos, because it will not get sold if the item can't be found by the buyers.
I have seen many auctions where it is not clear what is being advertised. Sometimes the sellers just write "Canon digital camera with a lens", and can't be identified which product they are exactly. Of course, someone who is familiar with photo equipment, can identify them by a very small detail, and by that they could buy them for a much lower price. But as a seller the goal would be to sell the items for the highest possible price, so let's get back to creating advertisements that sell.
An effective title and description are searchable and contains lots of useful information about the item for sale. First of all, the title should contain the item's exact name. (For example: Canon EOS 300D) If we're not sure about it, search it on wikipedia or on the manufacturer's site. Furthermore, we can include the extra accessories, condition, free postal cost or the price in the title (if we have enough space).
In the description we have lot more space for describing our photo equipment for sale. We should create the description like a pyramid: at the beginning we should write briefly about the item name, all the additional accessories, the condition and the price. After that we should describe our item in more detail: write about the product (product description, most important features, recommended for whom), about paying methods (what are the ways buyers can pay), about posting the item (where is the item, which countries are we sending the item, how much the postal cost is) and about warranty (if there is warranty, or if we accept returns).
Here are two advertisements as an example for a good and a wrong title and description:
Of course, they are just simple examples, and many more things can be included in the description. My general advice would be to browse other seller's advertisements from the same item-category, maybe we could find some good ideas we could use to improve our listings.