First of all you need a dailly routine, somthing simple so that you won't be tempted to skip. That's where we are going to start. First off invest in some inexpensive whitening toothpaste. (your probobly saying..."I already did that" Yea, we know but in a combonation of other things it will make your teeth beautiful.
You might want an electric toothbrush--Crest Spinbrush is only about $7.00--they work better. Use you whitening toothpaste to brush your teeth with your new toothbrush. Here is where everyone messes up...you brush for about thirty seconds and say ok, brushed my teeth. Here's my tip: turn on your favorite song and brush through the entire thing(about 3 minutes)
After your brushing take floss and floss in-between each tooth...you must do this AT LEAST every other night no matter how painstaking it is. After you have flossed buy some inexpensive mouthwash and swish it around in your mouth for about thirty seconds. Rinse with water and you are finished.
Crest whitestrips work great but if you have braces...well...thats kind of diffucult. Do this regimen even if you have whitened your teeth for a intense clean and a healthy mouth!