Sometimes when you shoot indoor with flash, especially at night, you get a cold stark flash look rather than the nice warm light that you see in the room. There is an easy way to capture more of the ambient light. Simply dial up the ISO and the flash will automatically reduce its intensity. You will then get a stronger mix of the ambient light, as what I did in this picture.
Of course, one can also get around this by manipulating the white balance settings, by either using the presets or the manual Kevin setting. But I find setting the ISO is the easiest and most direct way.