Traditional teacher evaluations -- full-lesson observations, write-ups, and debriefs -- are time-consuming and largely ineffective. As a principal, Kim Marshall found that mini-observations -- short, frequent, unannounced classroom visits, each followed by a face-to-face coaching conversation and brief narrative summary -- actually improved teaching and learning. With the benefit of hindsight, he shares ways mini-observations could be even more effective and shares some common observation practices he believes leaders should rethink.