I could initially see more green and it was generally only six inches to a couple of feet out from whatever I was gazing at. That gradually increased, particularly when I started using the exercises in Brian's Aura Seeing course. Not only did I start seeing a wider range of auric field, but I started seeing other colors, as well as varying densities of hue, and movements in the field while I was observing it.
I think my greatest improvements where when I started looking at auras throughout my day, not just when purposefully looking as part of my practice with the course materials.
I'm sure people find differing benefits and ways of using their skills, but for me it's very helpful to see how people are interacting, if they're engaged in and/or understanding what is being taught or presented and their general state of mind.
When I do healing work, it is incredibly helpful in ascertaining where energy is blocked, leaking, or slow and stagnant.
All the best with your practice!