It's my experience as an instructor and examiner for a long time, that you become much better at detecting how and when things are happening and when they are about to go pear shaped. You also pick up little tips from the people you fly with that you perhaps hadn't thought of yourself. If you are not careful however, this can lead to a gentle upward drift in what you require as normal standards from your students.
However, although your own awareness standards do improve, unless you are able to mix instructing with other work which involves handling, your own handling skills can degrade, and this particularly applies to examiners sadly.