One of my most used tool when I shoot portraits are the Lastolite TriGrip Reflectors.
The Lastolite TriGrip Reflectors are great for gently lifting the shadows in the subject faces when shooting their portrait. Usually my assistant is holding the reflector in such a way that the light beam is passing just infront of the person. I try to avoid direct light into the eyes since then it´s difficult to keep the eyes naturally open. Another great tool from Lastolite is their different kind of diffusors. A great example of their use is Thomas Ljungbergs portrait of the two sisters laying in the grass. He used a large diffusor Skylite Rapid 2×1 meter above the girls to create the smooth gentle light.