“Don’t judge a sushi restaurant after only one visit,” an aficionado once advised. Every day is different. Try it two or three times, at least.
To me, this advice might also apply to yoga teachers. No two classes are the same. Different asanas, different sequences, different classmates.
Still, having practiced yoga for a dozen years, having tried too many teachers to recall them all, I tend to judge quickly. I usually know after 30 minutes whether I would willingly pay money to study with that person again.
My quickest judgments come with the outliers: the master teachers and the mediocre ones. The majority of decent teachers, however, are harder to assess: they might say all the right things but leave me indifferent. Regarding these teachers, I try to follow the sushi advice … and squelch that so-so first impression and give them another day, another class, another chance.