So once you got that set up, let's render and see what we got. When rendering lights, I like to render one light at a time, so you can see what each light is doing and what's changing. As well, I like to click that little down arrow button and save each render stage so I can scrub back and forth in the render view and see subtle changes that are happening. I'm going to guess it's going to be hard for you to see a lot of the little changes I make here, but it really helps. Sometimes I hide old lights as I add new lights so I can see what that single light is contributing to the scene all on its own.
Think of it like playing 20 songs at once. 19 of them are playing various songs like Led Zeppelin, Rolling Stones, and other music that doesn't suck. But one of them is playing Celine Dion, and I tell you to turn off the Celine Dion one because that high pitch shrieking from Titanic song is going to make my head explode. It's going to be hard to tell which one is Celine Dion with all that other music playing. Turn them off and play them one at a time though and you'll figure it out. Shadows work the same way. Got a strange light? Narrow it down one by one trying to figure out which light or lights is making them.(Fig.06)
This isn't too bad. It's casting a decent brightness. The way the shadows are cast, they define the features of the face ok so far. Good enough to move on to the fill light. To do that I'm going to just duplicate the key light I made already (No need to keep setting the same settings over and over). I'll use the manipulator tool to position it so I don't have to rotate it around to aim back at the head. I may adjust where exactly it's aiming at though (Fig.07).
I'm going to turn down the lights intensity of this new light so it's not as bright as the key and then render and see what it looks like.(Fig.08 & 09)
To me, this seems way too bright. It's starting to wash out the model a little and it doesn't really define the model any better. So I'm going to go back and adjust the intensity until I'm happy with it. (Fig.10)
So here I've lowered the intensity of the fill light to around 0.2 and added a slight green tint to the light. I got the color from sampling from the floor and then lightening it a little. Next I'll add a rim light to help better define the model from the background and define some of the features of the model better. I will again duplicate the light, and in this case I'm going to turn up the intensity. I'm also going to add a little color. In the next image you can see how little color I tend to add. (Fig.11)
Here we are with a little bit of back light now added. It looks alright on the head to me but on the top of the pedestal, right above the vertically ridged part, the light feels too hard to me. So I'm going to soften the shadows up a little by turning down the intensity just a little more. It's just one little spot, but it looks off and should be corrected.(Fig.12)