Ian Edelman, the young creator of “How To Make It in America,” said he was given a word of inspiration by fellow producer Rob Weiss as they toiled for 14 months on the HBO series, which debuts Sunday. “The word is haberdashery, as in, ‘If this fails, you’ll be selling menswear,’ ” Edelman told the star-studded Cinema Society screening Tuesday night. Edelman said Harry Truman was a haberdasher before he became president — “Which just goes to show, if you follow your dream, you can become anything you want,” he told the likes of Adrian Grenier, Kevin Bacon and Kyra Sedgwick, Chloe Sevigny, Zoe Saldana, Josh Lucas, Michael Stipe, Leelee Sobieski, Steve Buscemi, Ed Westwick and Jessica Szohr, Tommy Hilfiger, Cynthia Rowley, Rachel Zoe and Chuck Zito, who has a funny cameo in the second episode. The after-party at the Bowery Hotel went late.