Here, in no particular order, are a selection of quick and simple tips and tricks to turn you into an iOS 9 power users. Master these and you'll find your iOS 9 productivity will go through the roof.
Know you've seen a toggle in the Settings app somewhere, but now can't find it? Just search for it. From the main screen in Settings pull down the screen to reveal the handy search box.
Annotate images in Mail
Tap and press on an image in an email you want to send and tap on Markup to add annotations.
Save a webpage as a PDF
From Safari click on the square with the up arrow to bring up the share sheet and then from the top icon strip tap on Save PDF to iBooks.
Request Desktop Site
From Safari click on the square with the up arrow to bring up the share sheet and then from the bottom icon strip tap on Request Desktop Site.
But there's a quicker way to bring this up. Press and hold down the refresh button at the top of the screen for a couple of seconds to bring up the option.
Perform simple calculations direct from the Search box. You can also do simple conversions.
Low Power Mode
I absolutely love this feature. You can find this Settings > Battery. More details on this feature here.
New "Back" button
When an app opens another app, there's now a handy "Back" button displayed in the status bar to speed your return to the previous app.
Apple Pay shortcut
Double-tap on the Home button to bring up Apple Pay.
Switch off "Shake To Undo"
I've never deliberately used the "Shake to Undo" feature in iOS. However, probably I've accidentally brought up the dialog box a million times. Now under iOS 9 I can finally turn off this feature. Go to Settings > General > Accessibility > Shake to Undo and toggle the switch.
Don't like the new lowercase keys on the keyboard?
Prefer the old keyboard? You can easily switch back to the old behavior by going Settings > General > Accessibility > Keyboard and toggling Show Lowercase Keys.
New iCloud app
iOS 9 comes with an iCloud Drive app that allows you to interact with the files you have stored in iCloud, but it's been strangely hidden by default. To reveal it go to Settings > iCloud > iCloud Drive and toggle Show on Home Screen.