Posted By:
BenOver the past several years, I've had the pleasure of trading with a significant number of board members here. Not surprisingly, the overwhelming majority of these trades have gone over extremely well, and both parties were the better for it. There have been, however, a few instances where this was not the case. Most of the time, this was simply chalked up to inexperience...because I believe it takes some practice to become a "good trader". So, I'm starting this thread not with the intention of bitching and moaning, but so that newbies to trading might have a few helpful pointers to make their future trades successful ones. After all, trading can be alot of fun when done the right way! So allow me to start us off with a few pointers of my own.
1. Common courtesy and politeness.
Good communication is absolutely crucial for good trading. Exercise common courtesy in your emails by starting with a greeting, and by addressing the person by their first name. By being polite and personable, the other person will be more inclined to work with you on a trade, and they will remember you for next time. Also, try to respond to emails within a reasonable amount of time. There's nothing worse than to be kept in suspense for a week and a half only to be told in a one-liner email "no thanks, but check for em on ebay!" And finally, after you've agreed to a trade, let the other person know when their cards have been mailed and when yours are received.
2. Hyping your cards
Avoid talking up your cards to your trading partner. If they are interested in trading for your cards, chances are they already know why they are special. The reverse is also true - refrain from talking down the other person's cards! This is a huge pet peeve of mine. There must be something good about them if you're interested in trading for them in the first place, so hold off on the "it's in terrible shape!" or "the registration isnt so good" comments....nobody knows these sorts of things better than the owner themselves. Talking down like this is a huge turnoff.
3. Book values
Insisting on having exact book value matches on trades is usually not the best idea - it makes trading very difficult, and usually slows the process down to a halt. After all, you are trading baseball cards, not standard catalogues.
4. "Make me an offer"
When someone posts a card for sale/trade and says "make me an offer", don't send them a one line email saying "how much?" Just make them an offer, and it better be a fair one because all a lowball will do is piss the other guy off, and jeopardize whatever chances you had of acquiring the card in the first place.
So those are my observations. Please add more if something comes to mind. Hopefully they come in handy to a few of us, so that future trades become easier and more fun for everyone. HAPPY TRADING! 
Ben