If you want to choose specific things (rather than all of them) to sync automatically to your Zune player or Windows Phone, use the Items I choose sync option. You choose the categories (such as particular genres of music or a picture folder), or you can choose individual items (such as a specific song, album, or video). Any changes you make to those selected items in your collection will be mirrored automatically on your player or phone. For more about choosing your sync options, see Setting your sync options.
If you have a Zune player, you can also sync friends from Zune Social—you'll get their Zune Card, and be able to play songs from their playlists (if the same songs are in your collection). But be careful, this can take up a lot of space on your player. The music for each friend's playlists can use up to 100 megabytes if you have a Zune Music Pass subscription. (Note that you can't sync friends to a phone.)
To sync specific items with your device
Bits and pieces still add up
Even when you choose to limit what you sync by using sync groups, it's still possible to choose more stuff than will fit on your device. If you run out of space, you're given the option to remove sync groups to make sure you can sync the things you want the most.
To review and edit your sync groups