System Preferences are the motivational speakers of your operating system. Don’t like something? The OS gives you the power to change! For those new to OS X, the System Preferences can be found under the Apple () menu in the upper left-hand corner of your screen. I’m not going to list every preference, but I am going to tell which choices you can make will have the greatest impact on how you use your Mac.
The big choices
General. Most choices here are purely cosmetic, like changing the highlight color, or how many items show up in the recent menu. In OS X Lion, however, you can make one important choice: whether or not to restore windows when quitting and re-opening apps. Unchecking this will stop applications from opening up the last-used files or web pages. This cannot be set on a per-app basis. Leaving this checked is good if you want to get back up and running quickly after a system reboot, bu bad if you’re giving a presentation and the last file you had open was a video of your bachelor party in Vegas.
Mission Control. The main choice here is if you want Dashboard to launch in its own space. Leaving this checked will keep it default (own space). Unchecking it means when you open the Dashboard it will work like it did in Snow Leopard, which is as an overlay on your main screen. I would have set it back to the Snow Leopard setting, but I’m using Josh’s excellent tip to map my Dashboard key to the Launchpad.
Security and Privacy. This is where you can turn Filevault encryption on. Previous versions of Filevault were fairly useless, but Filevault 2 (the one that’s included with Lion) is actually quite handy. For one thing, it’s a disc-level encryption that needs to be unlocked for your Mac to boot. I’d check this if you’re ever concerned about someone getting data from your Mac without your say-so. Also, you can turn your Mac’s firewall off and on from this preference pane.
Trackpad. Until Lion, I hadn’t realized the way I’d been scrolling was “unnatural,” but I’m glad Lion set us right in that regard. If the reverse scrolling drives you nuts you can set it back to unnatural, err, normal, err, the way it used to be, here. That said, I’d encourage you to give it a try for a few weeks. I wasn’t thrilled with it at all, but after a few days I quite liked it.
The little things
Desktop and Screensaver. This is where you can go to change your wallpaper and screensaver, as you may have guessed. But it’s also the place you can go to turn off the translucent menu bar.
Time Machine: Sadly, you can’t turn off Lion’s Autosave and Versioning features, assuming an app supports them. However, what you can change in Time Machine is the length of time before a file is locked. The default is two weeks after the last save.
Energy Saver: Here’s where you can change how often your hard drive and screen go to sleep. I’ve unchecked the setting to dim my display when using the battery, because I like my screen set to maximum brightness. However, leaving it checked is a good way to find out in a hurry when someone accidentally unplugs your laptop if you like to work in high-traffic areas.
Those are some ways you can customize your Mac without needing to use a third-party utility. Feel free to share your own suggestions about third-party preference panes that make things even better in the comments.