The iPhone's camera app shutter button isn't always in the most convenient place -- particularly if you're trying to operate it one-handed. You can use the volume button as an alternative, but there's another way to take a picture you might not be aware of.
This is a trick that's been around for years, but you might not have stumbled across yet (file alongside this one and this one). The two volume buttons on your iPhone headphones can also act as shutter buttons, which means you can snap pictures with one hand while holding your phone aloft with another, and it works with video too.
You can also prop your iPhone up somewhere and use the headphones as a wired remote. There are all kinds of situations when it might come in handy and save you from having to awkwardly juggle your phone around to reach the software shutter button.
Might be a idea to take advantage of this while you can...