The most important thing you can do to avoid badly stained teeth and  have a bright and white set of teeth is to use 
teeth whitening  systems that actually work. Below are 3 teeth whitening systems you  can try out.
1. Toothpastes that actually work
There are  many toothpaste brands that promise whiter teeth in less than 2 weeks.  Although toothpastes are abrasives, they do not contain enough whitening  power to whiten badly stained teeth or to help users get super white  teeth. Another reason toothpastes can't really whiten teeth is because  the saliva buildup inside your mouth dilutes the whitening gel in  toothpastes (at least those that contain peroxide)
Whitening  toothpaste from 'Aquafresh' whitens teeth very well, and 'Colgate  Visible White' works exceptionally well among various brands of  toothpastes. Make sure you brush for thoroughly for 2 minutes, to  maximize your whitening effort!
Toothpastes containing grapefruit  seed extract have been said to work wonders in whitening. Grapefruit  seed extract is a natural ingredient that will whiten teeth without  wearing off the enamel of your teeth. There are some toothpaste brands  that contain this ingredient and are packaged in big tubes for cheap  prices.
Don't rub any lime or orange peel against your teeth;  although this will "whiten" your teeth slightly, the peel is scrubbing  away a layer of your teeth. Brushing your teeth with table salt has a  similar but lesser effect.
2. Teeth Whitening Strips that actually  work
The Crest line of whitestrips products have been dominating  the home teeth whitening market for these recent years. Why? Because  they work wonders.
You can whiten your teeth up to 5 shades using  teeth whitening strips, depending on the concentration of tooth bleach  you choose to use. Starting at $22, Crest white strips come in many  varieties, including Standard, Plus and Premium Plus (in increasing  order of concentration of peroxide) this method is so affordable and  effective that millions have already used it to whiten their teeth at  home.
Another famous whitening strip that works is Maxodent, which  has a 14% concentration (higher than any Crest whitestrips currently  available in stores). Only dentists are allowed to give you such a  powerful whitening gel concentration. This stronger whitening power  allows anyone to whiten their teeth at least 5 shades in a shorter time.  The whitening effect of any whitening strip normally lasts 6 months,  but these Maxodent strips can last much longer. If you want to whiten  your teeth fast, Maxodent is a very recommended choice.
3. Dentist  Whitening Systems work.
Dentists offer teeth whitening of around  7-10 shades. The downside of this is that this can cost a minimum fee of  $300. Not a lot of people can afford to spend so much to whiten their  teeth. If you can afford this, you might want to have a try.
Teeth  whitening strips used effectively can get you better looking white  teeth for a much smaller price than what dentists use. Most dentists use  14% hydrogen peroxide (the same used in white strips such as Maxodent)  and charge just $500 for that.