What's the best way to maintain a Mac?
Make redundant backups, keeping at least one off-site at all times. One backup is not enough. Don’t back up your backups; make them independent of each other. Don’t rely completely on any single backup method, such as Time Machine.
Keep your software up to date. Software Update can be set to notify you automatically of updates to the Mac OS. Some third-party applications have a similar feature, if you don’t mind letting them phone home. Otherwise you have to check yourself on a regular basis.
Don't install crapware, such as “themes,” "haxies," “add-ons,” “toolbars,” “enhancers," “optimizers,” “accelerators,” “extenders,” “cache cleaners,” “defragmenters,” “firewalls,” “guardians,” “defenders,” “protectors,” most “plugins,” commercial "virus scanners,” or "utilities." With very few exceptions, this kind of material is useless, or worse than useless. The more actively promoted the product, the more likely it is to be garbage. The only software you should install is that which directly enables you to do the things you use a computer for – such as creating, communicating, and playing – and does not modify the way other software works. Never install any third-party software unless you know how to uninstall it.
The free anti-malware application ClamXav is not crap, and although it’s not routinely needed, it may be useful in some environments, such as a mixed Mac-Windows enterprise network.
Beware of trojans. A trojan is malicious software (“malware”) that the user is duped into installing voluntarily. Such attacks were rare on the Mac platform until recently, but are now increasingly common, and increasingly dangerous. There is some built-in protection against downloading malware, but you can’t rely on it – the attackers are always at least one day ahead of the defense. You can’t rely on third-party protection either. What you can rely on is common-sense awareness – not paranoia, which only makes you more vulnerable. Never install software from an untrustworthy or unknown source. If in doubt, do some research. Any website that prompts you to install a “codec” or “plugin” that comes from the same site, or an unknown site, is untrustworthy. Software with a known corporate brand, such as Adobe Flash, must be acquired directly from the developer. No intermediary is acceptable, and don’t trust links unless you know how to parse them. Any file that is automatically downloaded from a web page without your having requested it should go straight into the Trash. A website that claims you have a “virus,” or that anything else is wrong with your computer, is rogue.
Relax, don’t do it. Besides the above, no routine maintenance is necessary or beneficial for the vast majority of users; specifically not “cleaning caches,” “zapping the PRAM,” “rebuilding the directory,” “running periodic scripts,” “deleting log files,” “scanning for viruses,” or “repairing permissions.” Such measures are for solving problems as they arise, not for maintenance. The very height of futility is running an expensive third-party application called “Disk Warrior” when nothing is wrong, or even when something is wrong and you have backups, which you must have. Don’t waste money on Disk Warrior or anything like it.
