When you make a deal with the seller try to meet him on a public place
Do not trust anyone, always take precautions
Never accept payment by personal check, bank deposit or wire transfer, it is a sign of a scammer
Accept delivery by mail can be very risky, try to do it personally always taking precautions for your safety.
If a potential buyer asked a meaningless question without logic, do not answer, this person is a scammer.
When somebody says, I'm interested in what you're selling, I need information from your PayPal account and your email address, this person is a scammer, do not reply.
If anyone says, I'm going to buy what you're selling, I will pay by personal check because I'm not in town, so I need your personal information: full name and street address, be careful this person is a scammer.
When somebody tells you, you will have the check clear at your bank before proceeding with the pick-up, this is done for you to trust them, but what they need is your personal information, watch out these people are scammers.