The camera in iOS 7 has a burst mode feature that allows you to take up to 10 photos per second just by touching and holding the shutter button on your iPhone 5s**. If you can't tap the shutter because you are wearing gloves or are holding the camera at an odd angle, you can use the volume buttons as a backup shutter release mechsnism.
To take a single shot, just press and release one of the volume buttons. The camera app will focus and then snap your shot. Burst mode is equally accessible -- just press and hold either volume button and listen for the familiar rapid shooting sound.
Another neat little trick, if you have you iPhone headset plugged into the phone, you can use the volume buttons on the headset to snap a photo. It takes single photos, though, and does not activate burst mode.
**Burst mode is also available on older iPhone models, but the shot-to-shot rate is slower.