I have learned plenty this year but the biggest thing for me is probably old hat to most of you guys;gotta be able to judge the range of a target.
I took my 1st shot at a living animal in October, a small buck, shot right over his back at 10yrds using my 20 yrd pin, luckily he only ran 10yrds and this time my 20yrd pin worked well .

Since then I've bought a rangefinder, learned my paces, and I figure out distances when putting up the stand, instead of guessing at it when theres a deer standing there.