setting default umask

The default umask on Mac OS X systems is 022; I would like it to be 077. In Mac OS X the umask value must be specified in decimal; the octal value 077 is decimal 63. To change the default umask value:

1. Log into an administrator account on your computer
2. Execute the following line into the Terminal window:
   

   /usr/bin/sudo /usr/bin/defaults write /Library/Preferences/.GlobalPreferences NSUmask 63

3. Then execute the following line into the Terminal window:
   

   /usr/bin/sudo /bin/chmod 644 /Library/Preferences/.GlobalPreferences.plist

4. To return the umask value to the default setting of 022, use the following command:
   

   /usr/bin/sudo /usr/bin/defaults write /Library/Preferences/.GlobalPreferences NSUmask 18

Taken from Securing your computer: Macintosh Quick-Click Guide.