To get started. follow these steps:

Begin by choosing a distance that you can spot easily. The most common reference distance used by bow-hunters is 20 yards. Use this distance as your starting point for shorter or farther shots.
Using only the 20-yard reference, estimate the distance of the shot. Now fine-tune your estimation. Count toward the target in 10-yard increments. For example: if the target is 15 yards away, glance at your 20-yard reference point, estimate the halfway point , and then count toward the target in one-yard increments.
Compare the fine-tuned yardage estimation with your first estimate. Split the difference if you're within three yards.

For example: Using 20 yards as a reference, you estimate the target to be 25 yards away. However, when fine-tuning the estimation you count 29 yards. Splitting the four yard difference in half, you estimate the target to be 27 yards away. Start over if the figures are off by more than three yards.

Use the same method for longer shots. The more you practice this method, the less time it takes to complete the process. Seasoned bow-hunters use this method to estimate the distance of trees, logs, rocks and other objects.

No matter what method you use, never take a shot until you are satisfied with your yardage estimation.