There are alot of guides detailing how not to be scammed. For what it is worth here are my ideas on ways for sellers to avoid being scammed on ebay.
When you have sold an item the first thing to do is to check the buyers feedback rating. Don't always assume that because they have a high number or percentage that everything is ok.
Be on the look out for buyers who have purchased a large amount of low/medium priced items in a short period of time (30 days). This can be the first indication that something is up as they could be using a stolen credit card/bank details especially if they have used paypal as as means of payment.
It takes upto 30 days for people to receive their credit card statement and start the process of reclaiming the funds which have been used illegally to pay for items.Paypal will automatically pay back the money from your account.
Positive feedback in the above case does not indicate that everything is ok as some ebayers leave feedback as soon as they receive payment only to find out at a later date that they have been defrauded.
It is unlikely that the person in the above scenario will have a confirmed address, but if they do, always try and send items that can be tracked online to the confirmed address as you can claim back the funds from paypal should you be a victim of fraud.
If you receive a payment by paypal with an unconfirmed address look at the delivery name/address and also the log below which tells you that such and such has an unconfirmed address. Does both names match? If not beware as this could be a stolen card.
Also be on guard for people who are looking for quick delivery as it may be that they are using a stolen credit card and it is about to run out.
With new ebayers who do not have alot of feedback, it is prudent to ask for proof of Identity especially if the item being sold is of value.
Check the ebay address for your buyer against the paypal address given are they the same. If they aren't ask why.
Using the above criteria will not eradicate fraud, but it will certainly help in reducing it.
Be on your guard, most ebayers are honest people, but there are some that will use every trick in the book to defraud.
If it doesn't look right then it probably isn't, so ask the buyer questions
Enjoy your selling!!!!