OK, here's the follow-up to my rules for buying on eBay... these are the rules I follow for selling on eBay! Feel free to use these if you are selling, or plan to sell on eBay!
1. ALWAYS have a photo of the item you're selling. I can't stress this enough! I won't bid on an auction without a photo, and I won't put an auction up without one. You can either take a digital picture, or (if appropriate) slap it on your scanner, but have a photo! Two or more, if necessary.
2. If you don't have a photo of the actual item, say so in the auction description! I recently sold a bunch of Alex Ross DC Heroes posters on eBay, and mine were still in the original wrapping. I didn't want to take them out and unroll them to take pictures, so I hit up an Alex Ross website and got pictures of the posters from those, and I definitely stated they weren't the actual posters in my description!
3. NEVER sell anything you make yourself that uses copyrighted characters or content. The only exception to this would be original artwork. But don't make customized lightplate switches with Pepe Le Pew on them, or scan movie posters and print them out on your printer. If you do, and you're lucky, eBay will just shut down your auction. If you're unlucky, someone's lawyers will be sic'ed on you!
4. ALWAYS determine the postage cost before putting up the auction. Know how you're going to package what you're selling, and have the necessary supplies on hand. Use the UPS or USPS website to calculate shipping in advance, and err on the side of caution. I only sell to US bidders so I can ship Priority Mail with Delivery Confirmation, and I use my old zip code in Wisconsin for calcuating postage... and it's very accurate.
5. NEVER overcharge for postage, especially by adding an insane handling fee. If you have to pay for shipping supplies, fine, pass the cost on to the seller. But be reasonable about it! You can even add a buck if you're using the free supplies from the USPS. But if you charge a ridiculous amount for shipping, that'll cut down on your bids. My rule of thumb is, no more than $1 in handling charges... and that's not repeated for each item in a multiple-win auction.
6. ALWAYS ship some way that allows you to track the package. As I said, I use Delivery Confirmation with the USPS, whether I ship first class, priority, or media mail. It gives me a record of when a package was received, as well as a way for things to be tracked down if lost.
7. ALWAYS describe the item completely and honestly. When in doubt, choose the next lower grade to describe the condition. When I've sold comics in the past, I very rarely claimed anything was near mint... very fine was usually the best I'd claim.
8. ALWAYS keep track of your expenses to eBay. Every auction you submit, eBay tells you what your cost to them will be. Don't let it get out of control, or you could be in trouble!
9. START SMALL, and gradually — GRADUALLY - work your way up. My current goal is no more than 10 auctions up at any one time. Any more could be difficult to keep tabs on... and any less would be difficult to encourage multiple wins by the same bidder.
10. NEVER get someone to do a "shill" bid for you. "Shill" bidding is when an accomlice places a bid on your auctions to artificially drive them up.
11. ALWAYS check your email regularlly, and ALWAYS answer questions promptly. The longer you wait to answer questions, the worse the chances are you'll lose out on a bid.
12. ALWAYS print out shipping labels on the computer... never hand write them! And use all-caps... the post office is happier with that. And print your shipping labels on adhesive paper if you have it handy.
13. DECIDE when you'll leave feedback. Some sellers (myself included) like to wait to leave feedback on a buyer until they've first left feedback on the seller. I used to leave feedback on my buyers the same day I shipped their items, and I just got frustrated at all the feedback ratings buyers were getting, while not leaving any in return. Let your winners know your policy so they won't be asking you about it later.
14. ALWAYS email your winner to let them know when you ship.
15. ESTABLISH how long after receiving payment you'll ship. My policy is no later than the first business day after receiving payment.
16. DON'T TAKE PERSONAL CHECKS. If they bounce, you could get a $20 or more fee from your bank, and collecting can be hard. I only accept money orders or PayPal.
17. IF you use a reserve on an auction, either state what the reserve is in your description, or be ready to reveal it to anyone who asks. I don't use reserves myself.
18. RESEARCH what you're selling -- yes, I'm writing these rules out of order! Before you put an auction up, do a search on the same item, both current and closed, to see what that thing is going for. You can then decide what your starting bid should be, and what you can expect to get.
19. Use BUY IT NOW cautiously -- Let's say you're going to sell, oh, I don't know, a Superman Super Powers action figure. You've determined that this same figure in the same condition has sold in the recent past for $25. Now, you could consider starting it at $5 with a BIN of $25... and maybe someone will snap it up at that price. However, from personal experience, I can tell you that BIN prices work best when they're below the average selling price. However, you can't whine later on if you use a BIN and someone instant wins it for that price, and later you see another auction for the same thing closing for much higher. BIN prices work really well for items that are plentiful on eBay, especially if your BIN is lower than the starting price of other auctions.
20. Last rule -- at least for now! -- DON'T sell anything you don't personally have on hand! Putting auctions up for items you don't actually have is, in my personal opinion, slimy. Sure, you have someone promising they'll get this to you by the time the payment is received by your winner... but why take a chance? Only sell stuff you actually have.
I hope these "rules" of mine are helpful to those of you considering selling on eBay!
Jon