Get 1000 g + Cause A Ban To A Scammer

Spam on the trade channel offering to sell something or provide a service. For example, "LFW Enchanting, max skill".

Eventually, you'll get a tell from somebody who wants to scam you to sell the service or item cheaper than the market price.

He'll offer a deal like: "I've got only 1000 g today but I can pay you 1500 g more tomorrow. You can trust me." If you have trouble finding such scammers (who are plentiful) you can propose this kind of deal yourself.

Agree to the deal and make sure that logs indicate very clearly that he has agreed to pay you 1000 g more next day. Then he'll likely say "haha noob" and ignore you.

Wait until the next day and make a GM ticket explaining that you were a victim of a scam. Give him the following information:
- The name of the scammer
- The item scammed
- The time when this occurred
- The terms of the deal

The GM will likely escalate the ticket to the Blizzard specialist team investigating scams. Two days later, I got mail with the item included. (It was "Scroll of Enchant Weapon - Berserking - worth 1200 g on my server) The scammer presumably got a warning/ban. This scam is also completely safe.

A variation is to dualbox, "scam yourself" and launder the gold but this can be detected.