Identical twins Elsie Smith and Serenity Smith Forchion do everything together — including feats of breathtaking aerial acrobatics. The award-winning performers’ high-flying act snagged them gigs with Cirque du Soleil and Ringling Bros. and Barnum & Bailey, among other companies. After traveling the world, the two began teaching in Brattleboro and soon realized they had the recipe for success, founding their company, Nimble Arts, in 2003. Today the sisters head the New England Center for Circus Arts, known for producing top performers such as the trapezists, jugglers and contortionists featured in “Ruckus: A Cirque Spectacular.”