If you're doing your hair yourself, simply roller setting hair makes it look instantly dressier and adds body, too, especially if you backcomb a little.
Tonged curls always look romantic. For a simple dressed style on long hair, pull hair back to the nape, twist in on itself working upwards to the crown and inserting grips or a decorative comb into the pleat to keep it secure. Tease out hair at the crown a little for extra height and a slightly beehive effect.
Don't leave any sections hanging forward on the face, no matter what your style – they'll get sweaty or oily during the day and make you look sticky.