Trying to sync multiple Apple devices to the same Mac poses a number of challenges, including keeping each person's music, contacts, and apps separate, to say nothing of different levels Content Restrictions or the potential for messing up each other's preferences.
Luckily, iTunes contains several options to make managing multiple iPods, iPads, and iPhones on one computer easier.
Instructions in this article apply to iTunes 12 and higher.
How to Create Individual User Accounts
Creating a different user account for each person using the computer essentially creates an independent space that each person can use. If you do that, each person has their own username and password to log on to the computer, and can then install whatever programs they like, download whatever music they want, and can choose their own syncing preferences — all without impacting anyone else's files.
Here's what to do.
Open System Preferences under the Apple menu.
Select Users & Groups.
Click the lock icon to make changes.
You'll probably have to enter your administrative password.
Select the plus button to add an account.
Select the type of account under the pulldown menu.
If the new user is a child, you might want to create one with parental controls.
Enter the information for the new user and click Create User.
Repeat these steps for every person who will use the computer.
Since each user account is its own space, that means each user has their own iTunes library and sync settings for their iOS device. Because it's easy to understand, (relatively) easy to implement, and easy to maintain, with low potential for accidentally messing up someone else's setup — it's a good approach.
How to Create iTunes Libraries for Each Person
If you don't want to create totally separate user accounts for everyone in the house, you can just create separate iTunes libraries for each person. Using multiple iTunes libraries is a bit like having the separate spaces that the individual user account approach gives you, except in this case, the only thing that's separate is the iTunes library.
You won't get music, apps, or movies mixed across iTunes libraries and won't end up with someone else's content on your device by mistake. Here's how to do it.
Make sure iTunes isn't running.
Open iTunes while holding down Option.
The Choose iTunes Library window will open. Click Create Library.
Name the new library.
In the Where menu, select the location you want to store the new library.
Once you've saved the new library, iTunes will open. Repeat these steps to add as many libraries as you need.
The downsides of this approach are that parental controls on content apply to all iTunes libraries (with user accounts, they're different for each account). Adults are restricted to the most strict settings applied to their kids. It's also potentially tricky because each user's library is not as totally separate, and so there's potential for some confusion. Still, this is a good option that's easy to set up.
How to Manage Sync Preferences in iTunes
If you're less concerned about mixing the music, movies, apps, and other content put into iTunes by each person using the computer, using the syncing management screen built into iTunes is a solid option.
When you choose this approach, you select what content from each of the tabs in the management screen you want on your device. Other people using the computer do the same thing.
Connect the first device to the computer using the cable it came with and open iTunes.
Click the device icon in the upper-left corner of the screen.
Click Music in the Settings pane.
Click the Sync Music and Select playlists, artists, albums, and genres options. Uncheck Automatically fill free space with songs.
Select the items you want to sync to the device in each of the Playlists, Artists, Albums, and Genres sections.
Click Apply to save these settings and sync your device.
Repeat these steps for each device.
The downsides of this technique include that it only allows one setting for parental control of content and it can be imprecise. For example, you might only want some music from an artist, but if someone else adds more of that artist's music, it could end up on your device by mistake.
So, even though it's potentially a bit messier, this is a very easy way to manage multiple iPods.
How to Create Playlists for Each User
Syncing a playlist of the music you want and nothing else is one way to keep everyone's music separate. This technique is as simple as creating the playlist and updating the settings of each device to sync its own group of tunes. Here's how to set up playlists:
In iTunes, open the File menu, select New, and click Playlist.
Name your playlist, which appears under the Music Playlists section in the left pane.
Click one of the groups under Library to return to the music library.
Drag songs to the playlist title to add them.
Repeat these steps to create a playlist for each person's music.
Playlists can contain the same songs.
To keep everyone's music separate, they should only sync their playlist when they connect their devices.
Downsides of this approach include that everything each person adds to the iTunes library is mixed together, the same content restrictions apply to all users, you need to update the playlist regularly, and the possibility that your playlist could be accidentally deleted and you'd have to re-create it.