Selling anything on ebay needs quite a bit of work to succeed.
TIP NUMBER ONE: Take the best pictures that you possibly can. I don't know what products you are planning to sell, but if they are small then set up a dedicated "mini studio" with good lighting and the right backdrop to show off your product n great detail. One of the tent type foldaway thingies reflects light from the bottom, sides and top, which produces pictures without heavy shadows. Use a digital photo enhancement package on your computer to get the focus, brightness and contrast spot on.
TIP NUMBER TWO: In your description include everything: Dimensions, weight, condition, etc., because you do forget that your buyer is far away and cannot physically inspect what you are selling. That way too you are less likely to get embroiled in returns.
TIP NUMBER THREE: Put your item in the correct category listings. Ensure that you are not breaching any of ebay's selling policies because there are plenty of snoopers on there that will report anything iffy to ebay and you will get your listing pulled with no refund of fees.
TIP NUMBER FOUR: Send everything out promptly, very well packaged and ideally with tracking details for postage. If you don't and someone whines it hasn't been received (even when they have) then ebay sides with the buyer unless you have proof of postage.