RE: Help judging distance....
Though I have taken more than my share of animals, I never shot a 3-d very well until I learned to stop second guessing myself. Once I learned this I started outshooting my partners. Now, I shoot only one arrow, then use my rangefinder. I do not shoot a second arrow.
This year I peaked too soon and started sliding back. So I started shooting every two or three days instead of every day and I only shoot four arrows at each of three differing yardages. After these changes, my accuracy is back.
I hope these tips help.