What are some unique and effective ways to discipline a 1.5 year old?

I use a stern voice. I never hit. TBH, many times I wanted to hit or spank, but I felt it would just make things worse. Then I discovered that the stern voice was enough. Maybe because toddlers are used to that sing-songy tone we usually use to communicate with them, and they associate that sing-songy happy voice with fun and laughter, so when our tone changes, they realize something's wrong.