So I was bored and wanted something to shoot, my house mate is a keen Steven Sondheim fan, and having seen my cut throat razor in the bathroom and other clone photos, suggest I had a go at something like this.
Camera left is a hot shoe flash firing into a silver brolly with a red gel. I think it was my Sigma 500 flash. It is optically slaved and set at about half the power of the key light (camera right). My silver brolly is very ineffeicient, so it bleeds more power than my white brolly, so I reckon its close to 2 stops less power. The idea was to create a heavily coloured off-axis fill light, and create a strongly coloured shadow on the wall.
Camera right is a Metz 45, Mecablitz CL3 flash firing through a white brolly. Its triggered by an ebay radio trigger, not gelled, and set to 1/4 power.