Time for some semi-solicited professional advice here...

The "gold standard" for whitening teeth is the use of custom made trays and a carbamide peroxide solution (between 10 and 20+%).  There are multiple long-term studies to prove the effectiveness and safety of this method.

Don't waste your time or money with the products that use a light, laser or other gizmo.  There have been no independent studies that prove that this is any more effective than the method listed above - in fact, for any stability, you still need to get the trays made and use them.  The are far more effective at lightening your wallet than your teeth.

Crest White Strips are brilliant in their design, but have limitations - the teeth must be very, very straight for the strips to contact all surfaces, and they only work on the front six teeth in most people.  Virtually everyone shows between 8 and 14 teeth on the top when they smile, by the way.  If you are looking for a quick, inexpensive way to slightly brighten your smile, this is a good one.

Whitening Toothpastes:  They all work by being abrasive, so you must be careful in how long you use them for to prevent permanent damage or sensitivity.

Hydrogen Peroxide: Except in the specific case of professional formulations in a pH balanced gel, this is not a good option for tooth whitening.  If you plan to use it as a mouth rinse with any regularity, you need to dilute it with water (50/50 mix) to prevent chemical burns.  Remember - the first rocket fuels were hydrogen peroxide...  When used with baking soda as a toothpaste, it can be effective at decreasing the bacterial count in the mouth as well as some very mild whitening.

Bleach:  Don't do it.  Seriously.

Lumineers:  These things are useful for approximately 1 in 1000 cases.  The teeth need to require minimal color change, must be tipped inward and having some slight spaces between the teeth would help.  Otherwise you end up with monochromatic, opaque, bulky and overcontoured teeth.  Frankly, they blow.

"DaVinci Veneers": Actually, these are really a type of porcelain veneer (called feldspathic veneers in the industry) made by a particular lab.  They are very good at them, but there are another 100 labs that I know of that can do as well or better.  Another type of veneer would be an Empress veneer.  You can get excellent long-term results with these kind of veneers, as long as the dentist knows what they are doing.  Good rule of thumb - ask the dentist for before and after photos of cases that he/she personally performed.  And if they don't use a camera at the exam/consultation appointment, RUN!

A good long term solution to stain buildup (and some removal) is the Sonicare toothbrush.  You can get it online or from most big retail operations (Target, WalMart, Sam's Club, etc.).  I've been a Sonicare user for over a decade.  How much do I love it?  Oral-B/Braun sends me free powered brushes to use.  I happily BUY the Sonicare...

Please feel free to contact me personally if you have any other questions on this.

Doctor (not just a nickname) E.

Crest also puts out something with trays(like the dentist) that is supposed to whiten your teeth in 2 hours. It's not fun but it does work. I like it better than the white strips-less sensivity.

Pinay

If you use both youll need sunglasses to brush your teeth D just kidding

i found this great listerene pre brushing rinse it works amazing

that white light thing works very well.  well worth the $20

Suggestion to those using whitening stuff for your teeth.  I actually used to work with one of the whitening brands and here's the bottom line about them:

The way these things work is by pretty much eating away the (top) coating of your teeth (the dirty coating).  That's why when you use them your teeth get very sensitive.  You should have at least a 6 month period between treatments so that your teeth have the time to regenerate the coating.

One thing that seems to work with some people is baking soda.  Just put it on your toothbrush and brush it against your teeth.

Then there are other things you can do day-to-day, which yes, will cut into your habits but: cut out teeth stainers like red wine and Coca-Cola (you shouldn't drink that anyway).  And you seem to know about the cigarettes already so there you go.

I use Sonicare's whitening toothpaste + Listerine's new whitening mouth wash + Whitestrips all at the same time without problems.  The strips make my teeth super heat sensitive for a day or two afterwards, but that's about it.

Finally someone said it! Yes! the cheapest way to whiten your teeth  is baking soda.  i wet my finger a littel, put some baking soda on the finger an rub.  I have some groves in my teeth that the crest whiteing srtip didn't do much work on, the baking soda cleans it right up.  Oh, and it makes you teeth feel super clean like you were just at the dentist.  two things: don't do it too often (a bit rough on the enamelm buit not horrible) and it tastes kinda bad.  otherwise, its the way i reccomend to a fast whitining job.