If the reason behind bad taste in your mouth is common halitosis, commonly known as bad breath, then you should seriously maintain a proper oral hygiene, which will greatly help in solving your problem. You should brush and floss your teeth on regular basis. Make sure you clean your gums and tongue too, when you brush your teeth.
Always try to brush your teeth using toothpaste which includes salt and baking soda as its ingredients. Such type of toothpaste helps in getting rid of plaque and bacteria from mouth, which are major causes of bad taste development.
Sometimes, medicines also produce metallic taste, as a side effect. If you are taking some medicine on regular basis and feel that the metallic taste is caused by some particular medicine, then you should consult with your doctor and ask him to provide any alternate medicine that will not create bad taste in your mouth.
Deficiency of Vitamin C can also be a cause behind your bad breath. Therefore, try to consume citrus fruits or juices that contain citrus, such as grapefruit and orange, which will greatly help you in getting rid of bad breath, which is major cause of the development of bad taste in mouth. Also, you can take on-the-counter Vitamin C tablets, which can work almost same as citrus fruits. However, taking fresh juices and fruits is a better option to consider.
You can also take breath mints in order to get rid of temporarily developed bad taste, due to any strong-flavoured food. Using Lemon-flavoured candy can also solve your problem, or at least, it will diminish the bad taste in your mouth.
Create a mixture of hydrogen peroxide with water, or salt with water and rinse your mouth. Make sure you do not swallow the solution of hydrogen peroxide with water, as it is dangerous for digestion.