Human nature 101: If it looks good, it's gotta be good!
102. If you don't want to haggle, don't waste your time publishing an ad. If you have a bottom dollar price, ask enough to give you some haggling room.
103. The more trouble you exert ensuring that you answer all the potential customer's questions, including a test drive, the better your chances of removing the word "potential" from that customer's title.
104. The farther the person has to drive to look at the rig, the better your chances of closing a sale. Usually they come with a pocket full of cash....on fire...."burning a hole in their pocket" as the saying goes and don't want to drive all the way back home empty handed.
105. Cash in hand before it leaves your property, or certified bank draft and call the bank about how to ensure that they won't renege on its authenticity.
106. Expect them to require a bill of sale with engine and boat names, sizes, and serial numbers. Titling states like Texas require that for out of state registration and also requires signed, clear, titles (plural if outboard).Trailers usually just the license plate (TX) which is presented to a different taxing authority (county tax office where buyer resides). If you are in a non-titling state ask the buyer about his/her state requirements. If necessary get that all resolved before they make the trip to see you.
Last but surely not least, clean, fresh engine oil and outdrive lower unit oil. If your trailer has lube zerks or Bearing Buddies, ensure they are properly greased. If your tires are cracked and the pot. buyer is coming a long distance, $500 for a new set of SL tires could seal the deal, installed before he sees it.
That's what's worked for me over the years.