I wouldn't bother with whitening strips myself. For one, they are expensive, and second, they ony stay white for 6 months or so.

I drink coffee too. I use Arm and Hammer whitening toothpaste. It has baking soda, and it is Sensitive brand too. I brush very well for I'm guessing 3 minutes or so, then I use Listerine Flouride stuff.

So far my teeth are nice and white. I don't bother with that gelly whitening stuff, it feels gross on my teeth all greasy and stuff.

So, just get a whitening toothpaste and brush twice a day. Simple.