Celebs have always had to give good face, but in a time when plunging necklines and cutouts are dominating red-carpet fashion, it’s also about giving good sideboob , butt, hip, bicep, you name it. And that got us thinking: What kind of backstage treatments are A-listers trying hours — even days — before they step out of the limo and onto the red carpet? Think: injections to help cope with aching, stiletto-strapped feet, butt injections to give temporary lift, and virtual reality-led facials to help achieve pre-show Zen.