In general, we usually regard flash as a bad thing when used in low-light situations - it causes pictures to be one-dimensional and flat as the light is coming from a single direction, and reflecting straight back to the camera.

Flash causes things in the foreground to be really bright, and blacks out the background; it reflects off of shiny things, etc. etc. This is the primary reason we've avoided flash in our discussion about low-light photography done using natural lighting, even if it means dealing with camera shake or noise, will produce much better results.

Flash, however, does have one very useful application, and that is to control the light.

Even if you have plenty of light from room lights or indoors, light that you can control and direct yourself can sometimes look even better.

Take a subject like a person to do portraits,, and experiment with the lighting. First take a "regular" shot using just the natural lighting, and then if you want, a shot using the direct flash. After this, start getting creative. If you have an external flash, use it! If not, see if you can use a desk lamp or floor lamp for lighting, or barring that, play around with the orientation of your subject with respect to a light source like window ?

Summary:

Find a person and do a portrait session. If you have no photogenic friends, you may use an inanimate object or animal.

Take one "regular" shot using the available light. If you want, take a "flash" shot using the flash on your camera.

Get creative with your lighting sources. Use an external flash, a house lamp, or window lighting, and think about how to orient the light source and subject together, and also where you want to shoot from.

Some general ideas:
There are three main "directions" of lighting:

direct/front lighting (light hits front of subject),

sidelighting (light comes in from side of subject),

backlighting (light comes from behind subject).

Which type you get will depend on your position of THREE things: the light source(s), the subjct, and you, the photographer.

Direct lighting can be harsh, but you can generate "softer" light by either bouncing the light (reflect it off a wall, ceiling, or other surface before it gets to the subject), or diffusing it (shine the light through something, like paper or cloth).

A lot of the techniques that we demonstrated with flash can be done with a simple desk lamp/floor lamp, especially if you can angle them in whatever way you want. You won't get the super-fast burst of light that makes photos sharp, but you can still do things like manipulating the direction, bouncing off walls/ceiling, or diffusing.

Theme for this exersize is "And in Darkness, Light."