Success is never final, and often is situational. Find the cause of the success, and emulate that. Don't shun the classics, reinvent them. There is nothing new under the sun. Don't think you have a novel way of doing anything.
Communication needs remain constant, for example, but e-mail has changed the pace and nature.
Customer relationships are always key, but today's customers are better educated and more diverse than ever. Surround yourself with people you trust. Invest heavily in top talent in the legal, finance, and design areas. Use advisers, mentors, and confidants who are fabulously successful and empathic. If you subcontract or hire staff, don't rely on lengthy contracts and written agreements.