Not too much time today and therefore only one tip.
But it's a good one.
When using your flash on location. (When I say flash I am NEVER talking about the built in flash. The built in flash stinks - Is alway pointed directly at you subject - Is always too hard of too weak - Is the first thing they should improve or remove from a DSLR)
Where was I?
Oh yes, when using your flash in a close environment and you have no good ceiling or wall to bounce from, try the following.
Turn your flash about 45 degrees up and turn it backwards. YES backwards, don't say "Uhr" just do it. Now boost up your ISO to get a good lighting within the chosen aperture. Don't be afraid of noise, the flash will solve this for you. (unless your far away from your subject, I'm talking about 5 meters distance max here). Take the shot and notice how you got a nice, evenly, lit subject.
The higher ISO won't matter because you are using the flash. Normally you use your flash to be able to keep your iso down but it works both ways. Iso up and flash will give you a more sensitive film/sensor without the noise.
The photo you see here has been made using this technique. Notice how the white of the brides dress does not reflect your flash and dominates the picture.
Be sure to read my other Lessons and fire away your questions. Fire your flash towards some one else. I don't like to be photographed.