How to wash your hair
Ok, ok, you probably think you already know how to wash your own hair, but please bear with me, and you might learn some things to help you save time, energy and money.
First, most people do not need to shampoo their hair every day. The glands in your scalp produce a natural oil called sebum which starts at the roots of your hair and travels down the shaft, hydrating and protecting it. When you shampoo, you wash the sebum away. If you have shorter hair you can shampoo your hair more often, as the sebum will coat the shaft fairly quickly. If you have longer hair, it takes the sebum longer to travel down the hair shaft, and if you shampoo your hair every day, it will never reach the ends and will cause your hair to become dry. If you have naturally overly oily hair, you will need to wash it more often, but in most cases you can go every other day or every three days. It is just a matter of figuring out how long you can wait before your hair becomes oily.
Secondly, you only need to apply shampoo to the scalp. You don't need too much, about the size of a quarter. Wet the hair down thoroughly first, put the shampoo in your palm, rub your hands together and then massage into the scalp. If it does not lather right away, don't add more shampoo, just rinse it out and shampoo again (hence the famous lather, rinse, repeat as needed). As you rinse the shampoo out it will clean the ends of your hair. Make sure you rinse the shampoo really well, as if there is some residue it can cause irritation, itching and flaking.
Conditioner should only be applied to the midshaft and ends (if your hair is long enough for a ponytail, you would only need to condition the part after the elastic). Since the sebum begins at the scalp and travels downward, there is no need to condition the root area, and in some cases conditioning root to tip can produce oily hair.