The document discusses two essential design principles for curriculum development: thinking big and planning backward. It provides practices for implementing each principle, such as formulating a curriculum philosophy, mapping the curriculum scope and sequence, organizing content into big ideas and questions, and developing multi-year phased plans when thinking big. When planning backward, practices include setting SMART goals, identifying learning outcomes, developing aligned assessments, and creating learning activities. The overall message is that incorporating these principles into the design process can help educators work smarter on curriculum development projects.