1. Know your product or service fully
2. Be honest, transparent and be forthcoming
3. Avoid posting ads with 'PM for price'.
4. Always post high quality photos, they give people a good impression of what you deal in
5. Have an organized and simple way of addressing enquiries
6. Compile a list of frequently asked questions and have them readily available to ensure potential answers get answers quickly.
7. Be professional if you intend to be taken professionally
8. Ensure your transactions are documented and provide customers with copies.
9. Prioritize customer service
10. Respond promptly