4. Stop all the vibrating
Not for you (although you should probably get that checked out), but your device. In Settings > Sounds, turn off all of the vibrate options, because your device rattling around like crazy when a slew of messages arrives drains the battery like nobody's business. And anyway, there are dozens of annoying jingles you can choose from to announce to the world that someone's just sent you a message.
5. Tone down visual effects
Assuming you don't suffer from some kind of motion sickness or balance disorder, the various 3D effects in iOS 7 might excite you, and lead you to dream of the iPhone 6 projecting holograms on to your desk, in your own personal sci-fi movie. Right now, though, parallax is a pretty effect that drains the battery. You can use static rather than dynamic wallpaper to cut down the power drain a little; however, use Settings > General > Accessibility > Reduce Motion to temporarily turn off parallax entirely. (Note that this will also replace many system zoom effects with cross-fades.)
6. Turn off Spotlight
Like on the Mac, Spotlight on iOS is constantly working away in the background, indexing your data so you can easily find it later. Usually, that's great, but not when you're short on power. Settings > General > Spotlight Search enables you to turn off some or all Spotlight categories. Similarly, Settings > Notification Center might be worth a visit, although there's sadly no global off switch, and editing notification settings for all your apps might take more power than it saves, due to how long it takes.
7. Disable app refresh and updating
Under iOS 7, apps can refresh in the background and also update without you manually telling them to. When low on power, turn both of these things off. App refresh settings are found in Settings > General > Background App Refresh, and the auto-updating switch is called Updates and lives in Settings > iTunes & App Store.
8. Avoid games and other high-impact apps
Some apps burn through your battery much faster than others. If you're on the way home and low on power, reading apps like Kindle or Instapaper won't drain what's left of your battery terribly quickly. However, it probably wouldn't be a smart move to start playing your favourite TV series, or, worse, the latest 3D gaming blockbuster. In fact, even quite simple games often utilise complex 3D trickery, and so when in the red battery-wise, avoid them entirely.
9. Show your battery percentage
It's a smart move to keep an eye on your battery level, which a bar alone doesn't do a great job of. Therefore, go to Settings > General > Usage > Battery Percentage to activate a more precise read-out of what life your device has left. Note that for reasons best known to Apple, the iPod touch lacks such an option. All devices, however, will warn when your battery life hits 20 per cent and then 10 per cent; also, be mindful that even if your battery has a few per cent left in it, your device might automatically shut down anyway, so don't be doing anything too important when your iPhone, iPod touch or iPad is gasping for breath.
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