Why I Love Fill Flash!

One of the easiest things to do to improve your photographs is to use more flash.  Now I'm not talking about adding more units or overexposing images, just a general increase in the use of your flash whether built-in or external in more photos you shoot.
I almost never leave the house without my external flash.  Even on a bright sunny day - although it may not be a common thought to many - flash can improve your images by eliminating shadows and giving more pop to the scene.
In the photos below I shot them at ISO 800 in the caverns of Times Square.  The light wasn't that good and it was fading late in the day.  I shot them at F/5.0 (4.5) @ 1/60th.  The two images were made one second apart so you can easily see the enormous difference the flash makes.
On point n shoot cameras you can set the camera to Flash On to force the flash to fire in scenes when the software shuts it down.  In many of those same cameras you can even control the flash output and I'd recommend looking into that.
On DSLR's and the similar type cameras the flash units usually have their own exposure compensation as well it being on the body.