Advice for making the best of eBay depends heavily on whether you plan to buy or sell products, although some overlap does exist. EBay provides separate guides for each on its website.
Sellers should only provide feedback to buyers after first receiving feedback. This practice provides buyers an incentive to leave positive feedback, without which you have considerable difficulty selling products. Make sure that any prospective buyers are familiar with the terms of the deal, especially your return policy. Ensure that you have appropriate packaging before selling an item, and have all items weighed before selling. Only label brand new items as "new." If you or anyone else has used the item, you could receive poor reviews. Be aware that giving negative feedback likely results in receiving negative feedback; only give a negative review if you can accept that you might receive one.
Buyers should always check a seller's feedback before purchasing items. In particular, see if there are any common negative concerns that could apply to your purchase. Take reasonable precautions to ensure that the seller actually has the item, such as asking questions about it or requesting additional pictures. Research other websites for descriptions and prices to make sure that buying on eBay is the best option. Make sure you understand shipping and handling and any return policies before purchase.