Keep after them and keep putting them down. There is no substitute for actually killing game. I have killed XXX animals with a bow, and early in my Bowhunting career I blew several opportunities.
It does get better
Just learn from your mistakes and you will get more effecient. If you hunt long enough maybe you will never blow a shot, but I'm not sure how long that would be[8D]
Always enjoy each opportunity you get to Bowhunt as it Truly is a privledge.
Dan