I tried out a "Clamshell" arrangement with the lights today. Two strobes fitted with softboxes one below and one above both angled to converge the light on the centre of the subject, hence the "Clamshell".
The power of the two strobes was initially set the same but I upped the lower strobe a couple of clicks to get a bit more light under the chin.
Canon 5D2, Canon 100mm f2.8 Macro USM, 1/125th sec f6.3 ISO100
Processed in Lr CC
I gave these two images a dramatic B+W treatment which I really like.
Finally I placed a circular diffuser behind the subject and lit it with the third strobe. Before the subject took their place in front of the camera I took some test shots of the background, turning up the strobe until it was white, ideally I'd have liked some more distance between the subject and the background as the background became another light source and very slightly overexposed the subject's face, however it was so slight it was easily corrected in Lr CC.
I like the quality of light this arrangement gives, however the catchlight makes the subject's pupils into a rectangle, which some might think looks a bit strange.
It is a signature look though I suppose ...