Different hair types call for different shampoo regimens. However, the rule of thumb when using shampoo is to leave it on for a full five minutes. Less than that and you won't get the full benefits of using shampoo.
If you have dry hair, it's advisable to use shampoo every other day to allow your hair and scalp time to produce natural oils. However, if you live somewhere hot, try not to skip the shampoo to avoid developing dandruff. Instead, use a small amount of shampoo and follow it up with conditioner. If you have fine hair, try shampoos that contain wheat proteins and polymers. These ingredients make hair look thicker by coating the hair shaft. If you have oily hair, use warm water when rinsing off shampoo. Subjecting your hair to too much heat will only activate the glands in your scalp to produce more oil.
You may notice that your favorite shampoo seems to lose its effectiveness over time. This is caused by the build-up of proteins in your hair and scalp, contributing to what is called "shampoo fatigue." Use a different shampoo -- preferably one that is specifically formulated to remove build-up -- for a week or 2. Then switch back to your favorite shampoo.
If you'd rather not use another shampoo, there's a home remedy solution to eliminate shampoo build-up in your hair: apple cider vinegar. Soak your hair in a cup of apple cider vinegar and rinse with water after a few minutes. Do this once a week in order to get rid of shampoo build-up in your hair. You'll be able to continue using your favorite shampoo.