THE LOOK Below-the-chin sleek bob HOW-TO N.Y.C. salon owner Francky L'Official says to start by applying a dime-sized amount of anti-frizz serum to damp hair. Blow-dry hair in sections with a large round brush, pulling straight down and curling under on the ends. Apply a drop of shine serum for a glossy finish. INSIDER TRICK "Avoid using excess product on bangs as they tend to get oily faster," says L'Official. BUY ONLINE NOW Kerastase Nutritive Serum Oleo-Relax, $39; amazon.com.