How do you keep students engaged and curious?

Engaged students learn more and remember longer. How do you spark and keep curiosity?

Ideas that work across ages:

• Start with a question or a puzzle, not the answer.
• Connect lessons to real life and students' own experiences.
• Let students discuss and teach each other — talking deepens learning.
• Celebrate good questions, not just right answers.

What's your go-to trick for a lively classroom? Borrowable ideas very welcome.