Pick key employees and offer them the chance to participate in longer-term development programs. Make a big deal out of development and then pay the employee more money when they complete the program. Pay at market rates or more. Don't think that your benefits or loyalty will keep employees happy. Err on the side of generosity when you offer pay increases and never let pay be an excuse for an employee leaving.
Pay is never the real reason people leave a firm, but it sure makes a great excuse for employees.
And, most organizations can't defend themselves on this issue because they don't pay that well. Track the turnover of employees for every manager. Managers who have any significant turnover need to be educated and mentored and, if things don't improve, removed from managing people. Every survey shows that one of the major reasons people leave a firm is because of mistrust, dislike or incompatibility with the immediate manager. While these suggestions are in no particular order, if asked I would put this one first.