Not all clients are created equal, and sometimes it's a good idea to do a quick risk assessment before commencing work.
If a new client calls up in a rush and you've never heard of them, what steps do you take before jumping straight into billable work?
Figure: LinkedIn is your friend
The quickest and simplest way of performing a background check is to use the LinkedIn search feature:
Figure: Make sure you know who you're going into business with
For a more in-depth check or to see if their company is legitimate, do a Google search:
With this information you can then rank them from "Not a Risk" all the way up to "Huge Risk" (the kind with neon flashing lights and all) and decide whether or not to go ahead with the business deal.