Most companies' strategies deliver just a fraction of their promised financial results. Why? Business leaders make all-too-common missteps. Some over-rely on supposedly strategic structural changes (such as streamlining management layers) that produce only short-term gains. Others build strategies on incorrect assumptions. Still others never communicate their strategy clearly, leaving unit managers confused about priorities. And some get sidetracked by operational problems, devoting insufficient time to strategic decision-making. This HBR article collection shows how to avoid these errors. Here's a taste: Make sure information about how to execute your strategy flows to the people who must act on it. Articulate what your company will and won't do to compete. Test the assumptions underlying your strategic plan. Continuously monitor performance as you roll out your plan. Apply these rules, and you craft sound strategies and make the right midcourse corrections while executing them. Best, you elevate your company's financial performance to those ambitious levels promised by your strategy.