For Fuller Thicker Hair Like Jennifer Anniston

To get the look, stylist experts in UK's Cosmo, recommend using John Freida Lux Volume Shampoo & Conditioner & then spray damp hair with Lux Volume Blow Dry Lotion, focusing on your roots.  Partially blow-dry your hair upside down for added lift & then use a round brush at the roots.
(Darren Regan, senior stylist at the John Freida salon).