I had over over 10,000 feedback, 100% positive when I sold there. I don't encourage anyone to sell on that particular site, but if you do here's some general advice: use enough pictures, of the specific item you're selling, that there are no surprises. Describe it in detail, more (actual facts) is better. Include a description of any flaws or drawbacks in the item. Respond to every inquiry and concern seriously in a timely matter, no matter how ridiculous it seems. I also made the shipping costs prominent in the listing body, but my preference is free shipping and make sure that's written near the top. It's a selling point, and from the buyer perspective removes one potential common gimmick from the equation.

Some people like to use gimmicks, and add a lot of hype and huckster to their listings, some even going so far as to intentionally call into question their own literacy and knowledge. To trick a buyer into believing that the seller is too stupid to realize how valuable the item is for example. I don't hold with any of that but I do advise to make the listing interesting to read and to add informational value to it.

That's all I've got for you - good luck.