- Use Cyanogenmod.
- Install applications from the alternative FOSS market F-Droid. All of the applications below are available directly from F-Droid.
- Set up a network firewall with Droidwall.
- Use Firefox, with NoScript and AdBlockPlus add-ons.
- Set application permissions with Permissions (aka. Permission Denied).
- Send encrypted SMS with TextSecure.
- Encrypt your files with Android Privacy Guard (AGP).
- Send e-mails with K-9, which also supports PGP.
- Encrypt folders with LUKSManager (not on F-Droid?).