Speaking from experience, I believe I do well as a buyer, since I've won many auctions and bought various items at a good price. I'm not bad as a seller either (well, I believe I'd do better if I was living in a bigger country). So I would like to share some buying/selling tips with you.
Always check every item available before you decide to buy something.
i) Check condition. It would be better to buy items which are labelled as Brand New. Or Like New at least. Unless it's something extremely rare, then don't expect to find it in such conditions.
ii) Check location. The closer it is to your location, the faster it will come. And shipping costs are less too.
iii) Check prices. Always go for the lowest prices. But of course you should mind the conditions as well. Usually cheaper ones are in not so good conditions, so I believe best option would be to buy the cheapest Brand New.
Ask for a refund as soon as possible.
If in case your item won't come by the Estimated Delivery date, then ask for a refund. Keep in mind to ask for a refund NOT send the item again (if in case, the seller has the same item more than once of course). The reason is very simple, because there's a small possibility to receive your item after the Estimated Delivery date, which means the benefit will be double. You will have both your item and your refund as well.
I know some of you, you will say, Then I can ask for a refund, if I pretend I didn't receive the item, even if I did. My response here, would be to avoid doing it always, because eBay might realize something's going fishy with you if you never receive items, and not only you're going to be banned from eBay if they figure out what you do, but get in trouble with the law as well.
So it would be better to do it, when you actually haven't received the item within the Estimated Delivery date. Chances are like 1/10 for it to happen, at least from my experience.
Prefer bids rather than Buy Now.
i) For the main reason, there are more chances to buy an item at a lower price. If you can't find something else, and you want this item so much, then go with Buy Now. It's not bad.
ii) It's important to place your bid, within 10 seconds when auction ends. I don't say to disturb your sleep hours just for it, but if it's convenient for you, arrange your schedule like that, so you can be able to place the last bid within that small time frame. Of course if other bids have been placed meanwhile, check other items to see if there's a lower prize than the one you desire.
iii) And last but not least, place the minimum price available as your bid.
Do a review, about how much the item you want to sell, is being sold by other Sellers.
Of course it's not static, since sellers of the same item come and go. So you have to take your chances in this case, and place your item at the best lowest price available. Which means 0.01 dollar/pound/euro less, than the lowest price available of the SAME condition as well. For example if the cheapest item available, in a Brand New condition, costs $10.00 then place it at $9.99 if your item is Brand New as well.
If your item is common choose a Buy It Now price and only. If your item is rare make an auction.
The simple reason, why you should choose to make an auction in that case, is because you are going to attract 2 or more buyers aiming for that certain item, and if they are desperate for it, they might give as much as possible each. The earlier the bidding starts the better.
Post at least another picture except the stock picture.
The stock picture, doesn't give an accurate description of the item you own. So it would be better to post some more pictures, so the buyer could see how the item they are about to buy looks exactly.
Hope it was helpful!