A while back I photographed Vinny Jones. It was for a publicity shot for his TV show 'Toughest cops USA' The location was in London's East end and I had about five minutes to shoot the picture. I wanted the picture to reflect the feel of the documentary so I ws going for the urban gritty look. Vinny looks pretty mean anyway, so I just had to get the lighting right and then give it a grade to suit in Photoshop.
As you can see in the diagram I've made here, I wanted to highlight the edges of his face and shoulders, so I placed an SB800 at each side and a little back. I wanted a narrow beam of light so I moulded two sheets of blackwrap around each flash to give me the angle I wanted. Blackwrap is a fantastically handy roll to have in your bag. Very cheap and perfect for flagging off unwanted light. I recommend everyone to have some lying around in your bag, it scrunches up into a small ball when you're done with it and tucks away in any pocket. It's very tricky to execute this lighting without a stand in, unless your subject has plenty of time, which mine didn't, so I had to make sure I was all ready to go as soon as he stepped into frame. You don't need expensive lights for this, any small flash with a sync for a wireless trigger and a manual mode with power output steps up and down. You must work with your ambient lighting, most DSLR cameras only sync at a maximum shutter speed of 125th or 250th so be aware that in most cases you need to 'beat' the ambient or it will kill your lights. Some dedicated flash units will sync at faster speeds, but the power output at these faster sync speeds is compromised.