It’s a bit outdated as of iOS 8, but here’s an actual Apple Store Genius’s guide to improving battery life on your iPhone or iPad. Most useful tip has been to turn off Location Services and Background App Refresh for the Facebook app, which not only slowed battery drain but actually caused the battery percentage to jump.

Of course there’s also the official Apple guide to maximizing battery performance.

And if you were interested in the life of an Apple genius at all, there’s McSweeney’s Retail Therapy: Inside the Apple Store series, and words store staff can’t say to customers.