Great question! Having a great grouping during practice will allow you to gain confidence before going afield.
Here are some great clips and videos full of tips to help get you that smaller grouping you are looking for!
These videos will show you our routines that we use to get ready for bow season!
I hope you find these tips helpful!
http://www.growingdeer.tv/clips.php?ep=bow-shooting-practice-tips&#/bow-shooting-practice-tips (pre season tip to get your form set)
http://www.growingdeer.tv/archive/#/deer-hunting-focusing-on-the-kill-zone (tips on shooting from an elevated position)
http://www.growingdeer.tv/archive/#/bow-hunting-fine-tuning-before-deer-season (choosing the right equipment and ensuring your equipment is fine tuned)
http://www.growingdeer.tv/archive/#/deer-hunting-see-more-deer (practical bowhunting tips)
Growing Deer together,