If you want to improve it's no just about shooting lots of arrows, work out a plan for improvement with goals at the end.
When you go and practice decide before you go which area of shooting form you want to work on, do some focused work in that area at the blank bale or normal target and then enjoy some fun practice, I say fun because practice can sometimes be boring and can be your worst enemy towards development.
When you first start out shooting you see fast\\big improvements but once you get to a certain level the improvements are slow and hard to notice, but doesn't mean your not improving.