Lighting the Subject
Reflectors and Diffusers
Personally, Where there's enough light, I'll use a Lastolite diffuser to reduce the light falling directly on the subject and/or a Lastolite reflector to help fill in the shadows. Using reflectors and diffusers, more often than not, requires an assistant to accompany me as I tend to run out of hands quite quickly!
Although I much prefer to use natural light for close-up and macro photography, sometimes there really isn't enough to light the subject correctly or to freeze movement, in these circumstances I tend to turn to portable flash for help. Within the Nikon Creative Lighting System there are a number of good choices including two designed specifically for close-up and macro photography. In spite of this, my current tool of choice is the Nikon SB-910 Speedlight. Until the introduction of the SB-5000 the SB-910 was Nikon's flagship model and does a fantastic job of lighting almost any subject. In addition, it can be used to control the firing and brightness of other speedlights within the same system, so you can build quite a sophisticated set up that is both portable and cost effective.