I am a big fan of Docc Hilford's effects and writings because his effects are real-world. These are not pipe dreams or 'neat ideas', they are fully-developed routines that have been refined on paying audiences.
Personal Touch is devastatingly powerful and oh so simple to do. You can use this to reveal your spectator's innermost secrets and gain you some serious credibility. Docc says he uses this to get flight upgrades and VIP service in hotels, and I can definitely see why!
This is, and I don't use the term lightly, a reputation-maker.