It's surprising the way some people treat their hair. Instead of giving it the respect it deserves, they tug at it with their hair brush, secure it with plain elastic bands that stick to the hair, lick it, chew it, clean their inky hands with it, stick their pens in it, wipe that excess eye-liner off on it, and while shampooing, rub it, scrub it, pull it and generally bash it around before stuffing it under the full blast of a hair dryer. Phew! It's shameful. Just because they're not going bald in a hurry, they take it for granted. And then they wonder why their hair isn't a shiny, swinging, sexy mane like in the ads, in spite of using the same shampoo! Well, understand the facts of life. Hair is delicate, growing stuff which need to be handled with care. A lot of care.
It is not recommended to wash hair twice in succession, as often recommended by shampoo manufacturers. The first shampoo will wash your hair and the second will strip your hair of its nutrients. By repeating, you can irritate your scalp and overly dry your hair. HOWEVER, a long rinsing with water is a good habit, even if you are in a hurry; else, the hair will be dull and more sensitive to external irritants.
Use cold water as a final rinse; it will make your hair shinier. The cold water closes the scales that the hair has on its surface, which open when washed with hot water. Moreover, if your scalp tends to be greasy, cold water prevents dilatation of sebaceous glands and moderate sebum production.
Use mild shampoos if you want to wash often (they create fewer bubbles but this doesn't mean that they don't wash well; excess suds are more aggressive). Do not use children's shampoos, which are not soft but less galling; they contain over-greasing agents that make the hair more loose.
Use anti dandruff shampoos with care; they are more aggressive, can make hair less lively, irritate the scalp, and can actually increase the production of dandruff.
If you have forked hair (split ends), the only solution is to cut it and use a hydrating treatment to protect the new ends.