Summarize this article in one sentence.
You might accumulate yellow matter between your teeth if you are not flossing regularly. Flossing can instantly remove a lot of the build-up between your teeth that causes discoloration. Make sure to make flossing part of your daily routine.  Use a good amount of floss — it should be about 18 inches in length. Grip  the floss tightly in each hand, and move the floss up and down between each tooth. Curve the floss into a "C" shape, so that you are covering the entire surface. Use fresh sections of floss as you move around your mouth.  Do at least six up and down movements on each tooth surface. Be gentle — don't damage your gums. Whitening your teeth does not have to be expensive. You can use several items that you probably already have in your own home. One effective method is to make a paste out of baking soda and lemon juice. Baking soda can help balance the Ph levels in your mouth, and lemon juice is a natural sort of bleach.  You will need a few teaspoons of baking soda and a small amount of lemon juice. Mix them together until you reach a paste-like consistency (partly liquid). Then use a toothbrush to spread the paste onto all of your teeth. Leave on for one minute, then rinse your mouth thoroughly with water. Be careful not to brush your teeth too hard with this paste, as you may produce some abrasion on enamel. Baking soda can also be used to create a scrub by combining it with salt and strawberries. The salt will act as sort of an exfoliant to scrub gunk from your teeth. Strawberries contain a lot of vitamin C, which is good for breaking down plaque. To make this scrub, you'll need two to three strawberries. Mash them together, and add a sprinkle of salt and a dime-sized amount of baking soda. Spread the scrub onto your teeth using a toothbrush. Let sit for five minutes, then rinse. Hydrogen peroxide is common in most homes, and is often used for minor scrapes or cuts. It can also be used as an inexpensive method for whitening your teeth. Simply swish a very small amount in your mouth for a few seconds, then spit it out. Then brush your teeth as you normally would. In addition to strawberries and lemons, there are other foods that can help remove the yellow from between your teeth. Try using an orange peel. Before you go to bed, rub the peel of an orange across your teeth for a few minutes. The vitamin C will help to break down the yellow. You should see results within a few weeks. If you don't want to make your own whitening products, there are many that you can buy. Look for a toothpaste that specifically promotes its whitening agents. Also, look for a brand that has been approved by the American Dental Association. Your local drugstore will have many options for you. Some of these methods will give you instantly whiter teeth. But for best results, you should get in the habit of taking steps to remove yellow from between your teeth. If you take regular steps to promote the health of your teeth, you will see more significant and longer lasting results.

Summary:
Floss. Make a paste. Concoct a scrub. Rinse with hydrogen peroxide. Raid the refrigerator. Buy a whitening toothpaste. Get in a routine.