Professional development is not extra work without structure. To avoid sapping employees' energy and feeding scope creep, you have to build a program for career advancement. In the wake of the Great Resignation, many business leaders have frantically sought ways to keep their best talent on board. There's no one-size-fits-all solution, of course -- it depends on industry, available resources, business makeup, and at least a dozen other factors. There is one recurring best practice that seems to have consistent impact, however: Offer professional development. In other words, give your employees the opportunity to level up in their careers with skills training and credentialing.