Get your eye in
Definition 1 of 1
Pro Tip 1/3Sports Origin
Originally from sports, meaning to adjust your aim or technique through repetition. 
He spent the morning getting his eye in at the archery range.
Pro Tip 2/3Adjustment Period
Suggests a brief period of preparation or acclimatization to a task. 
Give me a few tries to get my eye in, and I'll be pitching perfectly.
Pro Tip 3/3Focus on Precision
Emphasizes precision and attention to detail through practice. 
The jeweler took time to get his eye in before setting the delicate stone.