Zac Posen, Betsey Johnson
Credit: Courtesy of Zac Posen/Twitter; Betsey Johnson/Twitter

New York Fashion Week hasn't even begun—it officially starts tomorrow night!—but that hasn't stopped designers from tweeting their excitement! The #NYFW TwitPics are coming in fast, with behind-the-scenes looks at everyone's work, from Zac Posen and Betsey Johnson, to Joseph Altuzarra and more—click through the gallery to see them all!