The goal of preventative maintenance is, of course, prevention. You want to prevent crashes, kernel panics and slowdowns. Doing a few simple chores on a regular basis will keep your Mac running smoothly and rapidly.

1. Backup your hard drive. Backup to an external hard drive frequently. Some people can go a week between backups; some should backup every day. It depends on how much data you can afford to lose if your Mac crashes.
2. Repair your permissions. Macs use a system of permissions to access files, and if the permissions get modified you may be unable to access some files, or the machine may bog down. Permissions can be modified when you download files or install programs. Repair permissions every month. To do this:
   • Go to Applications
   • Utilities
   • Disk Utility
   • First Aid
   • Repair Permissions
3. Do a fsck (file system check). Macs have an internal fsck utility that automatically runs a file system check and repairs any problems whenever you reboot into safe mode. To do this, restart your Mac and as soon as the chime sounds, press the “Shift” key and hold it down until you see a spinning black cursor. When it has come all the way up, restart it again without pressing the shift key. You should do this monthly.
4. Clean out your caches. As your Mac works away, it stores a lot of data that you use frequently in a cache, so it can get to it quickly. Over time, though, the cache gets unwieldy and bogs things down. It’s a good idea to empty the cache once a month or so. Go to your Library, select Cache, and delete all the files you find there.
5. Regular maintenance scripts. Macs automatically run regular maintenance at set intervals in the wee hours of the night. Scripts run daily, weekly or monthly. To take advantage of automatic maintenance, leave your Mac on at night. If you prefer not to do that, check into getting a utility that checks to see what tasks have been performed and runs necessary maintenance when you turn the machine on.

Performing these routine preventative maintenance tasks on a regular basis should prevent problems with your Mac and keep it in top running condition.