Some low hanging fruit: orders where the billing address is an exact match and it also matches the shipping address are probably the most likely to be legit.
usually, sure - this case is interesting b/c the fraudsters don't care about receiving the actual product
this is a really big field - most large companies that have to process tons of transactions will implement a big data approach - put together as much demographic and behavioral info about customer as possible and analyze risk. this is really impossible for small vendors
AVS which checks the billing address only really works in US. It's pretty much useless in any other countries in the world (it's partially supported by some banks in Canada and UK but that's it)
There are many more factors to consider though.