1. From Allure Magazine: Pull hair up into a Pebbles Flintstone ponytail at the top of the head and go to sleep with it this way. In the morning, pull out the band and iron out the kinks with a flat iron. Use sunglasses as a headband.
2. Sprinkle baby powder at the crown and roots.
3. Spray hair at the hairline with a volumizing spray, then pull hair back with sunglasses for your commute to work. Once in the office, pull off the sunglasses and voila! You have added body. (I've tried this with a sea salt spray and loved the results).
4. If you have straight hair with little natural curl in it, you may notice it falls flat often. To maintain fullness, you should consider cutting hair shorter (shoulder-length hair is especially flattering).
5. Invest in hair products. Volumizers will be your best friend, not only do they add body, but they tend to dry up your hair's natural oils. Spray them only along the hairline and at the roots -- they could dry out ends.