I try to take my pictues outside during the day, but if I have to take pictures at night, I use the close-up mode on my camera and have the flash off. I use my desk light and have the card on a white background.
After I upload my picture from my camera, I use Photoshop Elements to adjust the color, highlights and contrast. With the card on the white background, PE "knows" what the adjustment levels should be.
Hope this helps!