There's been some recent comments about off camera Flashes and the cheaper RF-602 or RF-603 wireless triggers. If you decide to go this route, remember that the trigger fits directly underneath the flash. Once you have this set up you can screw a light stand directly underneath the RF-602 receiver's 1/4-20 thread mount, but this means your flash can't be tilted and it doesn't provide a way to mount an umbrella.
If you want to be able to angle your flashes and mount an umbrella grab yourself an umbrella bracket for Speedlites and because the RF-602 or RF-603 receivers don't have a shoe lock, you'll need to look for umbrella brackets that have a built in shoe lock. Hopefully this will save you from buying the wrong ones. Check out the video below for more information on this. [Thanks Carl]
I'm using a few cheap umbrella holders that have locking shoes, and they start at about $4 dollars.
Adjustable Umbrella Flash Bracket