iPhone Camera Hole
Ever since the iPhone 5 came out, Apple puts three mics on all of the phones they release. You will find one near the speaker grill, one on the bottom of the phone, and the last one near the camera lens. They did this to ensure that you can capture the sound no matter how you choose to hold your phone.
Zigzag Side On Bobby Pins
There are two sides to bobby pins: the wavy and straight side. Many people put the straight side facing the scalp, but this is actually wrong. It might look cooler, but you can expect it to slide down all day long. When you put the wavy side down, it will hold onto your hair for a longer period of time.