by23856,
That is perfectly sporting of you...and being responsible to the deer. I know a lot of hunters who do exactly that. My brother will set out scent wicks at the distances he's marked from his stand. Me, I just take a field point or two everytime I go and shoot at a yellow leaf or a stick on the ground. If I hit or am off by an inch or two I'm golden. I like this better because it gets me better at judgeing yardage in case I'm in a different stand or don't have a chance to put up yardage markers.

But to answer your original question, it's a good idea and a good thing to practice.