You can call up Siri without even touching the iPhone's home button.
It's a feature Apple introduced a couple of years ago, but a lot of people still don't know about it.
It works with almost all of Apple's products. If you have an iPhone 6 or older, your device needs to be plugged in for this to work. If you have an iPhone 6s or newer, you can call up Siri no matter where you are. It even works on Apple's newer iPad Pro tablets.
Here's how to set it up.