Budget back light options

[addyboo]

I am on a tight budget.
What's the best type of back light to use for portraits, especially black backgrounds? I want to make my subject "pop" away from the background a little more....especially dark haired people.

Also if you can recommend any other lighting options for indoor portraits let me know. I am working with an SB600 with a flash trigger. I also sometimes have issues with my flash on black backgrounds. I can set up my umbrella on a white background and it snaps away with no hesitation. When I try it on the black background it doesn't. It blurs and doesn't like to click fast. Should I be setting my camera up different? Working on a Nikon D5000.

 

[tirediron]

The cheapest backlight will be an inexpensive second-hand flash triggered either via PC cord, or with a second flash-trigger.

I'm not sure I understand your issue with the backgrounds. Do you mean that the camera won't focus properly, or that the flash won't fire properly, or ??