Recently, I was encouraging the a student to create more width in their swing but in doing so they got rigid. Instead, I was looking for soft, natural wing-span where the arms and hands (particularly through impact) stretch to their maximum radius from our center. So I said- please try again and give me "extension without tension." I've since used this phrase with a bunch of students and it seems to be simple and efective. When something is good- I pass it on.
The next time your practicing I want you to think about reaching your arms freely, loosely. George Knudson was a famous Canadian Professional Golfer (finished 2nd in the Masters once!), great teacher and labeled as one of the best ball strikers of all times by his peers. He once wrote: "Centrifugal force generates a feeling of our arms being pulled out of their sockets." What great imagery and a feeling to search for. We don't force our arms out of their sockets- the feel and effect just happens if we let our body pivot whip our arms out, down and around on plane. To get the most possible extension, it can only occur withOUT tension. So say it with me- "extension without tension!"