What do you wish you knew about efficiency when you started teaching?

When I first started teaching, I had no idea how important systems were—both in and out of the classroom. I will never forget how tired I was at the end of every school day. Over time, my teaching strategy became focused on efficiency.

My guiding question became, “How can I effectively and consistently move the proverbial ball towards the goal and beyond, while expending the least amount of energy to do it?”

What are some tips you can share with new or novice teachers about being efficient? What advice would you give to new and novice teachers to improve efficacy while preserving energy?