Apply the Rule of 3

You achieve great success if you're willing to try new selling behaviors at least three times before passing judgement on the behavior's effectiveness.

Try No. 1 gives you the benefit of a new experience.

Try No. 2 allows you to apply what you learned and do it better.

Ditto for Try No. 3, but by now a deeper understanding of actions and outcomes allows you the benefit of wisdom and insight.

Apply the Rule of 3 to learning and sell more.