Since the days of gun hunting I have always marked trees, limbs or rocks with a small piece of orange flagging tape to mark known distances. Having a known 22 yard (or whatever) marker and a 31 marker helps make a fast decision as to distance.

Exactly how I feel. Shoot a quiet bow and you barely alert the deer to what he has got coming at him
They usually look to see what made the click up in the tree instead of jumping at the THWANG of the string.