Care and Feeding of Your Apple Watch
It may be a sharp-looking timepiece, but the Apple Watch is also a piece of highly technical electronics. Taking care of it involves more than a polish here and there.
Recharge
As I mentioned earlier, expect to top off the battery every day or so by connecting the included charging cable to the back of the watch.
If you want to actively conserve battery life, you can manually put the watch into its Power Reserve mode, which shuts down everything but a minimal digital time readout that appears only when you press the side button. This mode also kicks in when the battery level is below 10%.
To enable Power Reserve mode manually, swipe up from the bottom of the display to show Control Center, tap the battery level, and then tap the Power Reserve button (Figure 133).
To return to normal battery mode, press and hold the side button to restart the watch.
Restart
If the Apple Watch is misbehaving, it’s helpful to power it off and turn it back on again. To do so, press and hold the side button to bring up the power controls and slide the Power Off slider. Wait a few moments and then press and hold the side button again until you see the Apple logo appear.
In rare cases, the watch may freeze and require a force-reset. In that case, press and hold both the side button and the Digital Crown until you see the Apple logo.
Reset
If something seems especially screwy with the Apple Watch, or if you’re going to sell it or give it away, reset it to its factory settings. The watch’s data (including watch face settings and the like) is backed up automatically to the paired iPhone, so make sure the iPhone is backed up to iCloud or to a computer via the Finder (in macOS Catalina or later) or iTunes or before you reset it.
The Usual Resetting Method
The way to reset the watch is to unpair it from the iPhone, which performs a final backup (if possible) and then wipes the watch clean:
In the Watch app on the iPhone, tap the name of your watch at the top, and then tap the i
icon.Tap Unpair Apple Watch (Figure 134), and confirm the action.
Figure 134: Unpair the watch from the iPhone app to erase the watch. Enter your Apple ID password.
After several minutes, the Apple Watch is restored to its factory default state.
Reset Without the iPhone
If the iPhone isn’t available and you need to reset the watch, go to Settings 
> General > Reset, and tap Erase Apple Watch Content and Settings.
Restore the Watch
After the watch resets, pair the watch again:
On your watch, select a language and region and tap the Start Pairing button.
In the Watch app on the iPhone, tap Start Pairing and scan the (gorgeous) animated cloud on the watch.
Once the watch is paired, tap the Restore from Backup button (Figure 135).
Figure 135: Tap Restore from Backup to retrieve your old settings. Choose the watch’s latest backup and tap Continue.
Agree to Apple’s terms and conditions.
After following the remaining setup steps (enabling Location Services, re-adding cards to Wallet, and so on), the iPhone syncs data back to the Apple Watch. Soon, the watch is ready for use.
Updating the Watch’s Software
When Apple releases a new version of the watch’s operating system, watchOS, you’ll receive a notification. Open the Watch app on the iPhone and go to General > Software Update.
If the Watch Goes Missing
If the watch is nowhere to be found, locate it, lock it, or erase it using the Find My app on your iPhone, iPad, or Mac—or by signing in to iCloud.com.
Use Find My on an iPhone, iPad, or Mac
Starting with iOS 13 and iPadOS 13, the revamped Find My app is used to locate devices as well as people:
Open the Find My app on an iPhone, iPad, or Mac that uses the same Apple ID as the watch.
Tap the Devices button.
Tap the name of your watch to locate it on the map.
On the iPad and iPhone, actions appear when you select the watch. On the Mac, tap the i
icon next to the icon pinpointing the watch to reveal the actions.Select one of the following:
Play Sound: The watch chimes.
Directions: Get walking or driving directions to the watch’s location.
Notifications: Although this option is prominently placed, it doesn’t seem to do anything; the Notify When Found switch is inactive, even when the device is marked as lost.
Mark As Lost: Tap Activate to lock the watch and track its location, and optionally provide contact information and a message for someone who may find it.
Erase This Device: If you think the watch is unrecoverable—if it was stolen—erase its content and settings. Doing so prevents you from tracking it further, so consider this your last-ditch option.
Use Find My iPhone at iCloud.com
You can also use the Find My iPhone web app to find your watch:
Go to iCloud.com in a web browser and sign in.
Go to the Find My iPhone app.
Click My Devices and select your watch from the list.
Click Play Sound, Lost Mode, or Erase Apple Watch (Figure 136).
Cleaning
Apple’s advice on cleaning your Apple Watch is pretty commonsense: wipe the watch with a nonabrasive, lint-free cloth, wetting it with fresh water if needed.
Apple also recommends you dry the watch and band after exercise, which sounds as important for common courtesy as anything else.
The first-generation and Series 1 models are water resistant, so they can be taken into the shower, but Apple doesn’t recommend submerging them despite their IPX7 rating (which means they can withstand 1 meter of submersion for up to 30 minutes). Series 2 and later watches, however, are water-resistant to 50 meters, so you can safely shower or swim with them. But don’t subject them to high-pressure water.
According to Apple’s article How to Clean Your Apple Watch, if the Digital Crown isn’t turning or is unresponsive, you can run it under “lightly running, warm, fresh water from a faucet for 10 to 15 seconds.”