At the world premiere of
The Kennedys in Beverly Hills,
Katie Holmes channeled her inner Jackie O with a perfect, glossy coif. If you want to give your dark strands extra luminosity, turn to a silicone formula, but choose wisely. Mists work best on fine hair, while a serum amps up gloss for thicker strands. If you've got coarse or kinky hair, consider a natural oil.