If you are using the flash on your camera, you are probably used to getting results where people look fairly bad. Reason being, most flashes on cameras put out a very harsh light that leaves people looking rather severe. One way to get better results is to use a diffuser on your flash. You don't need anything fancy, you can make use of cheap available materials. What you are looking for is something that is white (although you can try other colors for "effect"), and fairly thin. In the past I have used coffee filters, kleenex, paper towels, T-shirts, and sheets of paper.

To use the diffuser, just hold it a couple inches in front of the flash, being sure that it does not end up in the picture. If you are using a digital camera where you can get instant results/feedback, you can try moving it closer or further from the flash to see how this affects your results. You can also try taking a picture without the flash diffuser to see how much of a difference the diffuser can make. I think you'll be surprised by how much better your flash photos end up looking.