If you're incorporating something like modernbill into the order system, you can then add in Fraud Guardian for screening.
Methods used for manual checking include IP tracing, location of IP to cardholder, calling phone number listed, domain queries, e-mails to purchaser, denial of "free" e-mail addys, and the list can go on & on. Phone calls though along with a check of the phone number listing will eliminate a lot of fraudulent orders IMHO. You can also require copies of Driver's licenses, passports, and CC front + back.
We have implemented fraudguardian in our system and its not 100% that effective. You do need to manually screen orders for fraud because some people will use the same ip and bounce their ip off that host. Manually screening the ips, email, address, telephone will help you alot.
Psychz Networks - Dedicated Servers, Co-location | GigePipe - High Bandwidth Servers | PhotonVPS - SSD Cloud True Layer 7 DDoS Mitigation | BGP Optimized by Noction Intelligent Routing | Asia-Pacific Low Latency Routes Los Angeles, CA (US West) | Dallas, TX (US East) | Ashburn, VA (US East)
We learnt the hard way that if we have even the slightest doubt about a transaction, we don't process it until we're 100% happy.
That's cut out most of the fraudulent orders we used to receive. Although we did get one at the end of last year that was clean on the credit card check, looked good on the IP address, had a postal address matched correctly and we even called the client on the phone to confirm further, but it was a fraud