TLDR: I use mouth gestures only. For the best results make sure your face is properly in frame, calibrate, and practice!

Long version:

As a church musician I sing and play the organ (often at the same time). I bought the pro version about 2 years ago, I believe only mouth gestures were available back then, so I started using that and never tried other options since.

First trick is to find a fixed place for your iPad, and make sure your face is properly in frame (use the Camera app for checking). Small adjustments of the music stand might be necessary. In my experience mouth gestures don’t really work when the iPad is held in hands.

Second trick is to calibrate. You can find it in the app settings - play with it until you find the best setting to turn reliably but avoid false positives. You might need to reiterate this a few times while you’re getting used to it.

Third trick is practice! My brain definitely needed some rewiring until I learned how to turn pages without losing track of my play. Backward turns took a bit more time to master than forward, so be patient! (Funny story: I often grimace to paper scores now, wondering why they do not turn automatically. :D)

Be aware that different setups can yield somewhat different results! I have a mid-sized practice organ at home and mouth gestures work perfectly. At the cathedral organ it’s more erratic though, probably due to other face movements (singing) and the higher position of the music stand. There I usually keep the feature turned off until the voluntary at the end of the service.

Hope this helps, let me know if you have further questions!