Here are some tips for new recruits (or anybody) for not getting scammed:
1) Never give away crowns/CE to people who you do not know well or at all, be it by mail, trade, etc.
2) It is strongly recommended against giving people money for unbinding, since some cannot be trusted. Check their legitimacy by looking in the bazaar, or asking around inconspicuously. Most people can be trusted, but just check to make sure.)
3) Whenever making a trade, do not press confirm before your trader puts their item in the box. I got scammed out of 6k crowns this way
4) If you are making an indirect trade (trade by mail, or you providing the unbind), do it with a friend you have known for some time, a trustworthy guildmate, or a well known seller (check bazaar)
I made this in response to a scammer thread in general discussion. Hopefully you don't get scammed. If you do, just report the player.
(If anyone has any other anti-scammer tips, feel free to share them.)
Slayzz basically hit all the important points, though I would stress one of them. When trading, if at all possible, do it via the trade window. That way you can see the actual item, and inspect it to make sure it is EXACTLY what you want before you enter in your part of the deal. Remember, both parties have to confirm to trade this way. Indirect trading is best done ONLY with people you trust, or as Slayzz points out, trustworthy guildmates. I mail recipes from Basil to guildmates all the time, and they mail me the cr back, because we all know each other. This is probably the only time I would ever trade via mail, unless, as Slayzz pointed out, they had a history of trustworthyness backed up by Bazaar forum posts.
Be careful, think about what you're doing, make sure you can see what item you are receiving, and make sure you are comfortable trading with the other person. I know you have to make trades sometimes with people you don't know, but try and avoid it if you can.