If your are shooting quarter size grouping's at 20yrds, 54/60 times. I think its time to sign up for some tournaments. I have the ball method. Golfball at 20-30yrds. baseball at 40yrds, and softball at 50. How I do this, I take rolls of vinyl(I own my own vinyl lettering company) I cut out circles these sizes with scissors and put on my targets. I practice with 3 arrows, I put all 3 in the circle I move to the next target. I do this repeatedly, then I randomly choose.

But as mentioned, usually you have an idea of what you did out of place that made the arrow miss. This is assuming the bow is set-up perfectly for you. Great shooting even if it is 20yards!!

I like the video camera idea as well, I bet that would help a ton.