EdTech is a perfect proving ground for prompt engineering. Classrooms generate structured signals (rubrics, standards, syllabi) and unstructured artifacts (essays, code, reflections). Good prompts can turn these inputs into reliable tutoring, grading support, and study planning—without leaking private reasoning or inventing facts. This article lays out a practical playbook that blends Chain-of-Thought (CoT), Tree-of-Thought (ToT), ReAct (tool use), and RAG (retrieval with citations), with copy-paste prompts you can deploy today.