First off, get rid of the rat's nest. Don't just rip a hairbrush through your tangles, though. That will cause split ends, breakage and a lot of hurt to your scalp. Instead, start brushing from the ends of your hair up to your scalp, holding the hair above the brush to prevent pulling.
Flip your head over and spray the roots of your hair with dry or waterless shampoo. There are tons of brands of dry shampoo, so make sure to choose wisely. Pick a dry shampoo that is made for your hair type, such as normal to dry or oily.
Let the dry shampoo sit for a few minutes -- or as recommended by the manufacturer -- then brush through your hair with a bristle brush. Voila! Your hair has gone from bedhead to brilliant in less than 10 minutes.
Washing your hair every day can strip your scalp of natural oils, making your hair dry and brittle. People with normal to dry hair typically only need to wash their hair once or twice a week, and people with oilier hair every other day.
If bedhead is a problem and you don't want to use dry shampoo, brush out your hair and throw it into a ponytail or loose bun. Oldies but goodies!
Hair that is slightly dirty is actually easier to style. The detergents used in most shampoos make hair unmanageable, dull and flat.