Be cordial and courteous. Keep vulgar to a minimum and please refrain from name calling.
What works for you may not work for others and just because there is a difference of opinion doesn't make one right over the other. If you state your difference, great, move on. This is a fairly new hobby and things are continually proving to be good or bad.
Relax this should be a fun hobby. Have some fun!!!
If you are conducting sale there are rules there that should be followed. Same goes for buyers.