So, how to get the update? There are two ways, one easy and the other one being a tad more complicated:
1. Wait for the OTA update
You should see something similar to this when iOS 11 hits your device
This is how the vast majority of iOS users will get the iOS 11 update on their devices. As usual, once the iOS update is available for your device your phone will inform you about this with a pop-up notification on your display.
Naturally, you'd want to click on the Details button in order to go to the Software update menu, which can be found in Settings > General. There you will see general information about the update.
At the bottom, you should see a Download and install button, just tap on it and follow the on-screen instructions, and you will be running iOS 10 in no time.
We've heard some old wives' tales that continuously opening and closing the Software update menu will let Apple know you are desperate to receive the update now, but the scientific community is yet to prove these unfounded claims.
Read more on the exciting new features that await you in iOS 11:
2. Install iOS 11 manually via iTunes
Users who are more comfortable the iTunes way can hook up their gear to the computer, find their device, and click the "Check for update" button, though you should receive a prompt for an upgrade on the fly. Just click the Download & Update button (pictured right below), and you will have your iPhone, iPad or iPod touch brought up to iOS 11 in no time.
Click the 'Check for update' button in order to see if iOS 11 is available for your device
Finally, we'd advise you somewhat reluctanctly to wait a little bit with the iOS 11 update. There have been occurrences when Apple's activation servers go down on account of the monster amount of immediate requests, and if you hit that button at the second the prompts appear, you might be left with a device that has no restoring in sight until the servers get up again.
Thus it'd be wise not to jump the gun immediately, but do it in the evening at home, or the next morning, depending on your country of origin, when the initial workload for Apple's servers has subsided.