The company culture you build has a major impact on how successful the business will be as it grows, writes Dan Schawbel, personal branding expert, at American Express OPENForum, a small business media hub.  One of the biggest trends in the past few years is workplace flexibility.   A new study by the Families and Work Institute shows that more than 75 percent of employers now offer some form of flex time. This number is up from two thirds in 2005.   In addition, 63 percent of companies allow employees to work from home at least sometimes, which is up from 34 percent. Schawbel…