My basic rules:
1. Cash in person only. No email negotiations (most people never show, so why bother).
2. No holding the item, with a slight modification: Call when you leave your house, (we know the approximate travel time), and I will hold it until you arrive.
3. I don't adjust my schedule for Craigs List buyers, too many no shows.
4. On deals I am buying, I never bombard the seller with questions, instead, I get in the car and drive. Most of the time, sellers take the easiest route. The guy with 100 questions gets put on the bottom of the list, while I am there in person closing the deal.
5. On stuff I am selling, I always take full size, high quality pics, and use a hosting site. C/L pictures ****. Pictures will sell your item.
6. Remember its free, not fleabay. So expect some hassles with flakes in return for it being FREE.