Advice wanted for a new seller listing equipment

Going to sell a few pieces of equipment here on Audiogon that I’ve acquired over the past year. What is your best advice for dos and don’ts when creating an add?  Can there be too many pictures? Does copying and pasting  the manufacture’s specs help? Do links to reviews help? Is keeping it short and sweet best when describing equipment?  Is it best to price the equipment in a way that shipping and PayPal fees are inclusive, or is it best to price more competitively with shipping extra? Should I price at my best price and state that I’m firm on the price or allow for negotiation so the buyer feels like he or she got a “deal”? Any sage advice would be greatly appreciated. Thank you for your time.