As the way the game is coached and played continues to evlove, so must your drills to keep up. If you want your quarterback (or any player) to be able to execute in games, you need to practice it.
In the video below, Coach Scott Isphording, OC & QB Coach at Ohio University goes into detail on five of the drills he uses for Developing a Dual Threat QB's Physical Skills.
His entire clinic is available on Glazier Drive
Focus on building relationships with the players you coach.
Establish a standard of performance and hold the players accountable.
Enjoy the process--control what you can control.
Develop toughness in your quarterbacks.
You're not a coach, you're a teacher--find out how your players learn. On the board? Film? Walk Through? "Watching" Practice?
Your job is to give them experience without experience. That is, help them learn without failing.