Mark E. Wilkinson, OD wrote an article that appeared on Review of Optometry called "Sharpen your Subjective Refraction Technique". This article has some great advice on maximizing efficiency and accuracy, and on minimizing common mistakes that can slow you down through you off during your refractions.

Using a standardized protocol allows clinicians to approach each refraction in a logical and sequential manner, eliminating simple mistakes that lead to clinician and patient frustration, and longer chair time. The protocol below was developed for the University of Iowa as its standard refraction technique and we have had great success with it in minimizing mistakes and delays.  We want to share it so that our fellow optometrists can be more efficient in their refractions and enjoy the positive impact it will have in the office." - Read the Full Article

Dr. Dexter's Take

As you see more and more patients during your clinical rotations, you will find yourself adapting and refining your subjective refraction technique as you take tips and tricks you've learned from your fellow colleagues.  Remember that patients will judge you on the quality of their prescription, so you better practice and perfect your technique! ~ Dr. Dexter