I use all of the following and all have their advantages for me at different times:
Direct payment to my UK bank account
Paypal
Western Union
sedo's escrow service
I also sometimes use escrow.com, but generally prefer to use sedo over escrow.com due to escrow.com's $40 wiring fee.
When dealing with people on DNF, paypal and escrow.com are the most common methods I use.